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EK-0RM05-FG-1

May 1982

120 pages

Original

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Document:	RM05 Fault Isolation Guide
Order Number:	EK-0RM05-FG
Revision:	1
Pages:	120
Original Filename:

OCR Text

EK-ORM05-FG-OOl

RM05 Fault
Isolation Guide

Prepared by Educational Services
of
Digital Equipment Corporation

Copyright © 1982 by Digital Equipment Corporation
All Rights Reserved
The material in this manual is for informational purposes and is subject to change
without notice.
Digital Equipment Corporation assumes no responsibility for any errors which
may appear in this manual.

Printed in U.S.A.

•

Class A Computing Devices:

Notice: This equipment generates, uses, and may emit radio frequency energy.
The equipment has been type tested and found to comply with the limits fc)r a
Class A computing device pursuant to Subpart J of Part 15 of FCC Rules, which
are designed to provide reasonable protection against such radio frequency interference when operated in a commercial environment. Operation of this equipment in a residential area may cause interference in which case the user at his
own expense may be required to take measures to correct the interference.
The following are trademarks of Digital Equipment Corporation, Maynard, Massachusetts:
DEC
DECUS
DIGITAL
Digital Logo
PDP
UNIBUS
VAX

DECnet
DECsystem-10
DECSYSTEM-20
DECwriter
DIBOL
EduSystem
lAS
MASSBUS

OMNIBUS
OS/8
PDT
RSTS
RSX
VMS

RMSS

FAULT ISOLATION GUIDE

SCOPE
This document is intended to supplement the existing RM05
documentation by providing additional trou~leshooting
information.
Problems are listed by symptom and solution
which should encompass the majority of all RMSS calls. If a
problem cannot be satisfactorily resolved through the use of
this manual, the FSE is urged to request additional support.
The RMOS has a VDE and NON-VDE version.
The di fference
between the two will be called out in this guide where
appl,icable.
Many specific error symptoms can be pinpointed to a module(s)
or component (s) •
The most obvious and known combinations
have been listed in this documant. This of course is not to
say all possibilities have been included.
The overall
accuracy of t.his document will be dependent on inputs from
the field. This document is intended to be used in conjunction with the RM05 Field Maintenance Print Set.

RM95 FAULT ISOLATION GUIDE

CONTENTS
1.0

2.0

PRELIMINARY ACTION
1.1

REQUIRED EQUIPMENT

1.2

GETTING STARTED

1.3

THINGS TO BE AWARE OF
1.3.1

File Corruption

1.3.2

Bad Packs

1.3.3

Environmental Problems

1.3.4

Bus Loading

1.3.5

Power Supplies

TROUBLE-SHOOTING AIDS
2. 1

ERROR LOG

2.2

SITE MANAGEMENT GUIDE/LARS REPORTS

2.3

CUSTOMER DISK PACK USAGE LOG

2.4

ON LINE DIAGNOSTICS

2.5

11/70

DIAGNOSTICS

2.5.1

CERHA

RH70

2.5.2

CZRML

Formatter

2.5.3

CZRMM, N, 0

Functional Test Part l, 2,

2.5.4

CZRMP, Q

Diskless Diagnostic Part 1

2.5.5

CZRMR, S

Dual Port Logic Test Part. 1

2.5.6

CZRMT

Compatibility

2.5.7

CZRMU

Performance Exerciser

2.5.8

CZRMV

Extended Drive Test

RMes FAULT ISOLATION GUIDE
CONTENTS (CONT)
2.6

3.9

VAX DIAGNOSTICS
2.6.1

EVRAA

Reliability

2.6.2

EVRAC

Disk Formatter

2.6.3

EVRDA

RMeX Diskless

2.6.4

EVRDB

RM0X Functional

POWER ON AND MOTOR SEQUENCE
3.1

POWER ON PROBLEMS
3.1.1

CB1 Trips

3.1.2

CB2 Trips

3.1.3

CB3 Trips
3.1.3.1

When CB1 Turned On

3.1.3.2

Immediately
Pressed

3.1.3.3

Shortly After Motor
Squealing Noise

After

Start

Switch

Turns

With

Is
A

Shortly After Motor Turns
3.1.4

CB4 Trips

3.1.5

CBS Or CB6 Trips

3.1.6

CB7 Trips

3.1.7

CB8 Trips

3.1.8

All DC Voltages Missing At Test Points and No
+29Y

3.1.9

+28V, -29V, +29V, -9.7V, +9.7V Are Either All
High OR Low

3.1.19

-46V,
Low

3.1.11

-46V, +46V And -16V Are Missing

3.1.12

Ripple Too High For Just One Voltage

+46V,

And -16V Are All

111

Ei ther

High

RMes FAULT ISOLATION GUIDE
CONTENTS (CONT)
3.2

DRIVE MOTOR
Motor Starts When CBl Is Turned On
3.2.2

3.2.3

'Motor Does
Pressed

Not

Turn

When

Start

Switch

3.2.2.1

+20v missing at Pin 3 of A1Q2, AIQ3,
A1Q4, and 9.7V is OK

3.2.2.2

+20V missing at Pin 3 of A1Q2, AIQ3,
A1Q4, and 9.7V is missing

3.2.2.3

+20V OK at Pin 3 of A1Q2, A1Q3,
A1Q4, and 208+ VAC is OK at Pin 2

3.2.2.4

+20V OK at Pin 3 Of A1Q2, AlQ3, AIQ4
but 208+ VAC is missing at Pin 2

Motor Overheats and Thermal Cutout Activates

3. 3

POWER ON AND MOTOR~ SEQUENCE VDE DRIVES

3.4

POWER ON PROBLEMS
3.4.1

CBl Trips

3.4.2

CB2 Trips
Short In +20Y Distribution

3.4.3

CB3 Trips

3.4.4

CB4 Trips
When CBl is Turned On
Immediatley
Turned On

After

Start

Switch

Shortly After Motor Starts Turning;
Also a Squealing Noise is Heard
Shortly After Motor Starts Turing
3.4.5

CBS Trips

3.4.6

CB6 or CB7 Trips

3.4.7

CBB Trips

3.4.B

All DC Voltages Missing and no +20Y

RM95 FAULT ISOLATION GUIDE
CONTENTS (CONT)

3.5

4.8

3.4.9

+28v, +29v, -20v, -9.7v, +9.7v Are Either All
High or Low

3.4.19

-46v, and +46v Are Both High or Low

3.4.11

-46v and +46v Missing

3.4.12

Ripple too High for Just one Voltage

DRIVE MOTOR PROBLEMS
3.5.1

Drive Motor Starts When CB1 Is Turned On

3.5.2

Drive Motor Does not Turn When St.art Switch is
Pressed
3.5.2.1

+29Y Missing but 9.7v is OK

3.5.2.2

+29Y is OK but 9.7v is Missing

3.5.2.3

+20Y is OK and 208 VACC is Ok

3.5.2.4

Motor Overheats
Activates

and

Terma1

Cutout

HEAD LOAD SEQUENCE PROBLEMS
4. 1

HEADS DO NOT LOAD AFTER UP TO SPEED TIME OUT AND NO
REVERSE CURRENT

4.2

HEADS DO NOT LOAD AFTER UP TO SPEED TIME OUT BUT HOLD
REVERSE CURRENT IS OK

4.3

CARRIAGE HITS FORWARD STOP, CB4 TRIPS, FAULT LIGHT ON,
AND HEADS STAY OUT ON PACK

4.4

CARRIAGE HITS FORWARD STOP, FAULT LIGHT ON, CB4 TRIPS
AND HEl~DS RETRACT

4.5

HEADS LOAD, HESITATES AND THEN CREEPS TO FORWARD EOT
(INNER GUARD BAND)

4.6

HEADS :LOAD, BUT UNLOAD, FAULT LIGHT ON

4.7

RTZ IS NON FUNCTIONAL

4.8

UNABLE TO SEEK TO PRIME CYLINDERS; 1, 2, 4, - 512

4.9

UNABLE TO SEEK TO 1466 (8)

4.19

UNABLE TO FORCE A SEEK ERROR WITH FTU TO CYL 1467 (8)

RM"S FAULT ISOLATION GUIDE
CONTENTS (CONT)

5 .. 9

6.9

4.11

HEADS DO NOT UNLOAD WHEN START SWITCH IS ~TURNED OFF,
START LIGHT IS OFF, PACK SPINNING

4.12

DRIVE MOTOR BRAKE IS INOPERATIVE

PCMER AND POWER FAIL PROBLEMS
5.1

MASSFAIL

5.2

AC LO - UNSAFE

5.3

DC LO - RM ADAPTER

ERROR BITS - CONTROL, STATUS AND ERROR REGISTERS
6.1

6.2

6.3

CONTROL REGISTER 176700
6.1.1

MCPE

Bit 13

6.1.2

TRE

Bit 14

6.1.3

Bit 15

STATUS REGISTER 176710
6.2.1

MOPE

Bit 08

6.2.2

MXF

Bit 09

6.2.3

PGE

Bit 10

6.2.4

NEM

Bit 11

6.2.5

NED

Bit 12

6.2.6

PE, UPE

6.2.7

weE

Bit 14

6.2.8

DLT

Bit 15

ERROR REGISTER 1

Bit 13

176714

6.3.1

ILF

Bit "0

6.3.2

ILR

Bit 01

6.3.3

RMR

Bit 92

6.3.4

PAR

Bit "3

6.3.5

FER

Bit 04

MIS FAULT ISOLATION GUIDE

CONTENTS (CONT)

6.4

6.3.6

WCF

Bit 05

6.3.7

ECH

Bit 06

6.3.8

HCE

Bit 07

6.3.9

HCRC

Bit 08

6.3.10

AOE

Bit 09

6.3.11

IAE

Bit 10

6.3.12

WLE

Bit 11

6.3.13

DTE

Bit 12

6.3.14

OPI

Bit 13

6.3.15

UNS

Bit 14

6.3.16

OCR

Bit 15

ERROR REGISTER 2

176740

6.4.1

DPE

Bit 03

6.4.2

DVC

Bit 07

6.4.3

LBC

Bit 10

6.4.4

LSC

Bit 11

6.4.5

IVC

Bit 12

6.4.6

OPE

Bit 13

6.4.7

SKI

Bit 14

6.4.8

BSE

Bit 15

7.8

ERROR BOOTSTRAP PROBLEMS

n.e

COMPATIBILITY
8.1

PROBLEM DEFINITION

8.2

CAUSES

8.3

ERROR SYMPTOMS

vii

RMI5 FAULT ISOLATION GUIDE
CONTENTS (CONT)
9.9

DATA BASE CORRUPTION

11.1

DRIVE NOT READY OR DRIVE HANGS

11.9

DUAL PORT PROBLEMS

12.0

PACK ERRORS

13.9

UNEXPECTED ATTENTIONS

14.9

ADJUSTMENTS

15.9

FLOW DIAGRAMS/TEST POINTS

viii

1.0

PRELIMINARY ACTION

1.1

REQUIRED EQUIPMENT

The following equipment
RM05 in minimum time:
1.

should

available

troubleshoot

Spares Ki ts
a.
b.
c.
d.

Spares Kit 11 29-23600
Spares Kit 12 29-23601
MBA Controller Kit
RHXX Spares

Scratch Pack

CE Pack

Field Test Unit

Maintenance Print Set

Manuals (on micro fiche) and/or Micro fiche reader.
a.
b.
c.
d.

30-17107-00
30-17108-00

MP0175

RM05 - Service Manual - EK-RM05-SV
RM05 - User's Guide
- EK-ORM05-UG
BK7BIE/F Technical Description Manual- ER-BK7B1-TM
BK7BIE/F Illustrated Parts Breakdown - ER-BK7BI-IP

Special Tools - other than in Spares Kit ,2
a.
b.
c.

15" *2 Phillips screwdriver
"C" Ring Removal/Replacement Tool Set
Heavy Duty Spring Replacement Tool (spring hook)

DVM

Oscilloscope (calibrated)

10.

Field Service Tool Kit with dental mirror and penlight.

11.

Diagnostics - up to date.

1.2

GETTING STARTED

Customer Inputs
Many problems can be eliminated at this stage by doing a
comprehensive investigation of the symptoms.
Obviously, the
object of the questions asked will be to determine whether there
was really a hardware malfunction, or if the pack, operational
procedures, or software are at fault. The questions will vary in
each situation, but some of the major points are listed below. It
is also advisable to verify the answers you get by other means if
poss ible.
1.

What are the apparent symptoms?

How often does the problem occur?

Can the problem be demonstrated?

(If so, do itl)

Can the problem
scoping) •

increased?

Has any disk related hardware or software been changed
recently?

Did this problem ever occur before the change? Using the
troubleshooting "tools" described in Section 1.1 and the
customer input, you should be able to determine whether
you actually have a problem in the RM05 subsystem.
If
you do, use Section 6 of this documentation to help
isolate and fix the specific malfunction.

frequency

1.3

THINGS TO BE AWARE OF

1.3.1

File Corruption

(For

easier

Frequently the disk is blamed for a file or task that no longer
loads or runs properly. While this can be caused by hardware, the
softwa re usuall y is at faul t.
If no device er rors are shown on
the console or errorlog, check the following key points:
a.

Is this a relatively new disk created by Preserve or DSC?
(both utilities have bugs that can cause file corruption
in the way bad blocks are handled, never trust a new
disk)

Is this pack any good?
A block may have just gone bad
and a read only exercise may pick up a bad header or data
check. Run either the Performance Exerciser (CZRMU) LOAD
AND START 204, "R" COMMAND, SWR - 3 for a 11/70, or for a
VAX the Formatter (EVRAC) "Read All" Command.
WRITE
PROTECT THE DRIVEl I I

Has the affected software been changed recently?
If device errors are shown, keep reading.

1.3.2

Bad Packs

It is amazing how many calls result from a previously trusted pack
suddenly giving errors.
The symptoms can vary according to where
the bad area is (header, data, etc.). The customer is responsible
for pack maintenance inc1ud ing bad block mapping, and keeping a
backup pack.
Look for similarities in the failure that indicate
it may happen during the same function and, if diagnostics run
clean, ask the customer to use a backup pack.
Obvious bad areas
will show up on Errorlog provided it is not Errorlog or the system
image that is bad.
1.3.3

Environmental Problems

This is a broad field that covers temperature, power and
electromagnetic radiation.
Power and grounding are the most
frequent problems, so verify that the configuration has not been
recently changed and pay attention to when the errors occur. L60k
for heavy equipment on the same p~ (or close by), plant
shutdowns, idle time etc.
In general keep your eyes open; radios;
forklifts (the spark coil), and computer room air conditioners
have caused problems.
If you have reason to suspect environment,
the only way to be sure is to consult an local environmental
specialist.
1.3.4

Bus Loading

A.C. Unibus loading can cause virtually any error on any device on
the Unibus and thE~ fast devices see it first.
The symptoms are
usually intermi ttent, and diagnostics usually don' t fail.
The
major clue is to look at a working bus with everything running
(with a scope, hopefully), and look for dropouts in the signals
large enough to cause a gate transition.
See the Unibus
Troubleshooting Guide (on microfiche-red section) section on AC
loading for more detail.
1.3.5

Power Supplies

Check all supplies for voltage with a DVM if available.
Then
scope for ripple on the supplies; a primecause of intermittents.
Also check the connections. See table 3-1.

2.g

TROUBLESHOOTING AIDS

2.1

ERROR LOG

This is one of the most valuable and least used tools for system
maintenance.
If you don't know how to run it for the particular
operating system, the customer and DEC software personnel probably
wIll.
The procedure should be entered in the Site Management
Guide.
There should be a software manual on site deta:iling the
operation and printout of the Error Log.
NOTE
Be certain that the error file for the
time of the failure is on the disk
you're using, and that error logging is
terminated so that the current file is
available
to
the
errorlog
report
generator.
Otherwise, you may miss the
errors you are looking for.
Error log will aid in determining:

2.2

Was there actually a hardware error?
filter out corrupted file type problems.

This

helps

you

What is common between errors?
The bad blocks and time
of day environmental problems show up here, as do most
semi-solid hardware problems.

How often did the error occur?
Tells you how likely it
is that you will see 'a diagnostic failure.

What was the system doing at the time? Is one particular
task or function always happening at the time of the
fa i 1 ure?
Are there system or other dev ice er ror s
involved?

What do the error symptoms indicate?
This gives you a
pre - d i a 9 nos tic i n d i cat ion 0 f wh at to 1 00 k for, 0 r
exercise harder.
On intermi ttents, this may be all you
have to work with.
SITE MANAGEMENT GUIDE/LARS REPORTS

Look up the disk history in the LARS reports or maintenance log.
Pa y spec i a 1 at ten t ion to wh a t ad j us tme n t s we r e mad e c:lnd wh i c h
parts were changed. Correlate this to the information you have
from the customer.
It is not unusual to find that the error log
indicates a problem starting
immediately after the last
maintenance on the device.
Also, check information on head
alignments against the customer's disk pack usage log in
situations indicating unreadable packs.

2.3

CUSTOMER DISK PACK USAGE LOG

Customers should keep track of pack usage, formatting, backups,
and bad blocks. This information is quite useful when· looking for
a potential pack problem.
Verify that the customer does look for
and identify bad blocks on a regular basis.
2.4

ON-LINE DIAGNOSTICS

These diagnostics are generally quite easy to run and can be of
great help in si tuations where the customer does not want to
release the system.
Unfortunately, they are installed at sysgen
time and if the system doesn't have them, you won't be able to put
them in easily.
The diagnostic operating manuals are usually
found in the customer's software manual set.
2.5

OFF-LINE DIAGNOSTICS

In many cases, off-line diagnostics will be the only available
tool. Consequently it is a good idea to be very familiar with the
ind ividua1 di agnostics and exactl y what they test.
The 11/70
diagnostics listed are all off-line but the VAX diagnostics;
Reliability, Functional, and Formatter can be run on line
providing that a scratch pack is mounted on the tested drive(s).
At the time of this writing, the current diagnostics for the RM05
are:
PDPll DIAGNOSTICS
tZRML - RM02/03/05

Formatter

CZRMM - RM02/03/05

Functional Test 1

CZRMN - RM02/03/05

Functional Test 2

CZRMO - RM02/03/05

Functional Test 3

CZRMP - RM02/03/05

Diskless Diagnostic Part 1

CZRMQ - RM02/03/05

Diskless Diagnostic Part 2

CZRMR - RM02/03/05

Dual Port Logic Test Part 1

CZRMS - RM02/03/0S

Dual Port Logic Test Part 2

CZRMT - RM02/03/0S

Compatabi1ity Test

CZRMU - RM02/03/05

Performance Exerciser

CZRMV - RM02/03/0S

Extented Drive Test

VAX DIAGNOSTICS
EVRAA

Reliability

EVRAC

Disk Formatter

EVRDA

RM0X Diskless

EVRDB

RM0X Functional

There are many techniques in using diagnostics but the most common
are "buildup" and "breakdown".
The buildup approach is commonly used when the failure is
catastrophic and a work ing system is "bui1 tup" using diagnostics
to verify each section, in an effort to find the failure by
starting with known good equipment and gradually adding the
unknown elements.
The "breakdown" approach to diagnosticS' is generally applied to
intermittant problems where basically the system works" but it
gets errors.
A general exerciser is run to get an indication of
the cause of the error, and then the suspect sections are
exercised with more specific diagnostics until the failing section
is isolated.
Neither of these approaches is perfect in all cases, as the
diagnostics generally overlap and assume that other parts of the
system work.
However, if you are aware of the 1imi tations, the
diagnostics can be an effective isolation method. You will find a
more detailed description of the diagnostics in this section and
an indication of the proper ones to use under the Error Bit
Section 6.0.
2.5.1

CERHA

Listed As:

RH70 Controller Diagnostics

Special Requirements:

Functional Drive and Scratch Pack.

Test Description:
Tests the RH70 using a disk drive
transfers and some register- check.
Suggested Use:
When a controller
working RM05 is available.

for

suspect

data
and

Comments: This diagnostic uses Cylinder" of the disk, and could
give errors if the media is bad.

2.5.2

CZRML

Listed:

RMe2/03/05 Formatter

Special Requirements:
Test Description:
Suggested Use:

A working RM05 subsystem and scratch pack.

Formats disk and updates the Bad Sector File.

Pack formatting and updating the Bad Sector File.

Comments: Be sure the scratch media is properly formatted at all
times because possibly the next time the system may not be able to
format. A pack with a known good format is invaluable when trying
to isolate a read problem.
To access the Bad Sector File utility routine, star.t the program
at 2e4.
2.5.3

CZRMM, CZRMN, CZRMO

Listed as:

RM02/03/05 Functional Test Part 1, 2, & 3

Special Requirements:
1.
2.

Formatted pack for Parts 2 and 3.
Certain areas on the pack must be error free.

Test Description:
These diagnostics test RM Adapter
tested wi th the :Oiskless Diagnostics. It also tests
read/write and servo logic.

logic not
the dr ive

Part l:
Tests error detect log ic, error abort log ic, look ahead
register, seek command, and offse~ command.
Part 2:
Performs wr i te and read of header & data; I sector wr i te
header and data, write check header and data, write and write
check of lis & 0's, format of multiple sectors, error logic,
mid-transfer seeks.
Part 3:
Performs write and write check data;
0's and lis, write
and wr i te check mul ti pIe sectors, wr i te and wr i te check wi th
implied seek.
Also error logic (HCE, IVC), write current tests,
peak shift tests, write and read each track, read and write check
multi-sectors in offset mode.
Suggested Use:
1.

Verify logic in RM Adapter not tested by Diskless 1 & 2.

Check basic drive read/write and seek functions.

Comments:
This program will disturb the header format of a pack
if not halted properly with a Control "C".
7

2.5.4

CZRMP, CZRMQ

Listed as:

RM02/03/05 Diskless Controller Part 1 & Part 2

Special Requirements:
Dr ive interface cables must be plugged in
and dr ive power turned on.
Test Description: Parts 1 and 2 combined, verify the operation of
the RM subsystem up to the drive interface. No specific tests are
performed on the RH70 and it is assumed to work.
Suggested Use:

To detect errors and faults in the RM Adapter.

Part 1: Tests basic handshaking; register transfer; error detect
logic; command decode; port reguest; attention logic; control
seqencer.
Part 2: Tests additional
sequencer; ECC logic.

error

detect

logic;

CRe

logic;

data

Comments:
1.

The drive is used for unit selection.

The multiple sector transfer logic is not tested as well
as the drive interface.

2.5.5

CZRMR, CZRMS

Listed As:

RM02/03/05 Dual Port Logic Test Part 1 & Part 2

Special Requirements:
1.

2.
3.
4.

Dual Controller Option.
Dual Controller Test Cable PIN 70-10507-02.
Power off drives not being tested.
Operator intervention - Part 2.

Test Description:
Part 1 tests the ability to seize and release each port.
also checks the timeout release.

Part 2 tests the duration of the timeout release and the port
select switch which requires manual intervention.
Suggested Use:
log lc.

To test the basic operation of the port select

Comments:
Use Performance Exerciser CZRMU to
dual port operation. See Para. 2.5.7

test the dynamic.;

2.5.6

CZRMT

Listed As:
Special

Compatibility

Require.en~s:

Formatted scratch pack.

Test Description: . This diagnostic is designed to detect the
following conditions which most commonly cause incompatibility
between drives.
1.

2.
3.
4.
5.

Head mis-alignment
Positioner lateral mis-alignment
Spindle/pack interface runout
Improper level of write current
Incorrect addressing of read/write heads

Suggested
Use:
This
program
is
obviously
incompatibility is suspected between drives.

used

when

Comments:
Funct:ional Test Part 3 and Extended Dr ive Test 20
should be run first to eliminate electrical problems with the
drive (write current). If errors then occur with this diagnostic;
it can be assumed that drive incompatibility is attributed to
mechanical mis-alignments or tolerances.
2.5.7

CZRMU

Listed As:

RM02/03/05 Performance Exerciser

Special Requirements:
1.

Forma tted pack. Packs using tests 16, 17, and 21 out of
defaul t mode, of the Extended Dr ive Test, will give data
compare f~rrors.

Addresses of known bad spots on the pack.

Test Description~
Performance Exerciser is a good, general
purpose, operating system like exerciser that maintains a high
activity rate on a RM05 subsystem.
It has two basic modes that
are selected by the "Si ze" parameter.
"Si ze" is the number of
words transferred per read or write order.
Data Mode:
Default mode and selects "Size", depending on
available memory, up to 8192 words. This mode transfers multiple
~ectors per command rather than single sector transfers.
For most
efficient run tim1e:
Parameter "Random" = 1 and the SWR
000001.
Change parameter "Passes" to 99 for long runs. Load and start at
II:

204.

Seek Verification Mode: Selected by setting "Size" to 256.
This
exercises the servo more than Data Mode since only one sector is
transferred per command.
9

Suggested Use:
1.

As a final overall subsystem checkout.

To surface intermittents and give additional error and
status information.

To check for multiple drive interaction.

To check customer packs for bad spots not logged in the
bad block file.
See Para. 9.8.
WRITE PROTECT THE
DRIVEI1! Load and Start at 204, SWR= 3 and "R" Commana:-

Dynamic dual port testing and SWR = 00~001.

use seek verification mode

Comments:
1.

This is the
exerciser.

In many cases it will be faster to isolate problems with
the lower level diagnsotics, as they, exercise isolated
sections faster and more thoroughly.

2.5.8

best

data

transfer

test

and

c)ver

all

CZRMV

Listed as:

RM02/03/05 Extended Drive Test

Special Requirements:
formatted pack.

KW-11P

Clock

for

timing

tests,

and

Test Description:
Test assumes a working RH and RM Adalpter and
exercises the mechanical and data transfer ability of t.he drive
i tse1 f.
The sector/track addressing and posi tioning portions of
the drive and RM Adapter are thoroughly checked.
If a }(W-IIP is
present, the mechanical timing of the drive is verified.
NOTE
Test 11 is an extensive positioning test
and Test 21 is a stress test of the R/W
and Servo system. They are not run in
the default mode and aust be selected by
the operator.
Suggested Use:
1.

When mechanics of a drive are suspect.

When RH/RM Adapter tests have shown no er ro-rs.
up" approach)

Checking mechanical performance during P.M.
10

("build

In conjunction with Performance
drive interaction problems.

Exerciser

isolate

Doing servo adjustments by modifying the parameters, LC,
IC, R for test 1 or 2.

Comments:
1.

Timing tests run regularly can track mechanical wear.

A better mechanical exerciser than Performance Exerciser
due to run time and operation.

Not a good RH/RM Adapter check as all commands are not
used extensively.
CAUTION
17, and 21 a1 ters the data
pattel~ns when used alone.
This causes
data compare errors if the pack is used
for Performance Exerciser.
Always run
Test 28 last to restore the pack (that's
why test 21 is not run in default mode).
Test

2.6

VAX

2.6.1

EVRAA

Listed As:

16,

DIAGNOSTICS

RK06/RK07/RP0X/RM0X/RL02/TUS8/RX02 Reliability

Special Requirements:
A formatted pack which is not "Mounted"
(VMS) with a volume name o~ "Scratch" or "Diagnostic".
Test Description:
sections.

This

program contains

five

Qualification - verifies the drive
support all disk drive commands.

Seek Timing
this gives the average seek times in
mili-seconds, from cylinder "0" to each prime cylinder
(1,2,4,8,16,- 512).
If there are two drives under test
from different terminals, the seek times are invalid.

Media Test - Write and Write Checks 5 patterns every
sector on the disk (except home and bad sector files).
It doesn't report bad sectors listed in the bad sector
file. After all the sectors have been written , the test
goes into a mode wi th random patterns and random disk
addresses ..

RM03/05

tested

will

Multi-Drive Test - tests up to 8 drives, transferring
random data to random addresses to all drives in a
concurrent mode. The function sequence is:
a.
b.
c.
d.
e.

Drive clear
Write random data
Write Check data
Read data
Data compare

Conversation Mode - allows the Field Engineer to design
and run simple test routines. Selectable functions such
as Seek, Read, Wr i te, Wr i te Check can be run up to 8
drives simultaneously with selectable or random disk
addresses and data patterns.

Suggested Use:
As a final overall subsystem checkout.
Also to
give additional status and error information for intermittant
problems.
Comments:
2.6.2

Run Functional EVRDB for worst case seek testing.

EVRAC

Listed As:

Vax Disk Formatter

Special Requirements:

Diagnostic Supervisor reference manuals.

Test Description:
Formats the pack and wr i tes
File. It is broken into six areas.

the Bad Sector

INIT - This section is run prior to all sections.
It
assigns a channel, builds a device dependent table, and
determines if the media is a scratch pack or not.
Init
also adjusts buffer sizes.
If in user mode (VMS), only
one track transfers are done. If in stand alone,
multi-track transfers are done.

PACK INIT - Format and writes a zero entry Bc3d Sector
File on all sectors of the last track. After reading the
Bad Sector File, the pack is formatted one track at a
time.

CAUTIONS
a. This section should never be run
unless the user verifies the disk
subsystem is OK and the Bad Sector Pile
is missing or corrupted.
b. This section has to be used to format
new packs which do not have the Bad
Sector Files written.
c. The new Bad Sector File is not
written until the end of the Verify
section.
3.

FORMAT - Reads and validates the Bad Sector File and then
formats one track at a time.
If the Bad Sector File is
not read, the program is aborted.
.

VERIFY - Reads and validates the Bad Sector File and then
reads the whole pack.
Any bad sectors found are flagged
and entered in the Bad Sector File.
If the Bad Sector
File can not be read, the program is aborted.

READ ALL - Reads every sector on a pack and pr ints the
data errors found. This is ideal for checking user packs
that may have bad spots that are not flagged.
As a
precaution, WRITE PROTECT THE DRIVEl

FLAG BAD - Allows for the manual update of the Bad Sector
File.
CAUTION, if this section is used , the home block
will be rewritten with a label of ·Scratch".
This
section is great for updating the Bad Sector File when
bad sectors show up only .under VMS or diagnostics but not
with the Formatter.

Suggested Use:

Pack formatting and updating the Bad Sector File.

Comments:
This program can rendor customer packs useless. Beware
of all implications and inform the customer of your intentions.
2.6.3

EVRDA

Listed As:

RM03/05 Diskless Diagnostic

Special Requirements:
The drive interface must be connected with
the drive power tur.ned on. Diagnostic Supervisor.
Test Description:
This diagnostic consists of 80 tests Which
verify the operation of the RM Adapter up to the drive interface.
It does not test the dr ive interface (RD and sections of the CS
module) except for the drive select lines that are used.

Suggested Use:
To verify the operation
subsystem independent of the drive.

of. the

Comments:
This diagnostic should
diagnosing disk subsystem problems.

2.6.4

always

RM03/05

disk

fi rst

when

line.

used

EVRDB

Listed As:

RM03/05 Functional Test

Special Requirements:
Scratch
Diagnostic Supervisor running.

pack

mounted

and

Test Description:
This diagnstic contains four test sections
which can be selected via a section switch in the Start Command
line.
1.

Data Transfers - Executes all data transfer commands and
verifies header logic. It also checks the addressability
of all sector/tracks and the error detect logic.

Seek Tests
This section contains positioning tests
which verify seek, recalibrate, offset, and r~eturn to
centerline command fUQctions. These test throughly check
out the servo electro-mechanical hardware.

Timing Tests - This section verifies the pack rotational
speed; minimum, average, and maximum seek times.

Manual
Intervention Tests
Tests all operator
interventions; pack acknowledge, read in preset, operator
address plugs, and write lock switch.

Suggested Use:
Verifies logic not tested in the RM Adapter with
the Diskless Diagnostic and tests basic drive functions such as
read/write and seeks.

3.0

POWER ON AND MOTOR SEQUENCE NON-VDE DRIVES

This section concerns from the time CBl is turned on, the start
swi tch is pressed, and the dr ive motor comes up to s·peed.
The
success of troubleshooting power on problems is dependent upon
thorough and careful visual observations. A general inspection of
all areas is in order for any power or motor problems.
1.

Check all circuit breakers CB6, CB7, and CB8.

CBl, CB2,

CB3,

CB4,

CBS,

Check for blower motor operation.
Inspect the primary
air filter at the bottom of the drive for need of
cleaning and also check the absolute filter air pressure.
If the air pressure is low, check for air leaks and/or
rep 1 ace th e f i 1 t e r • Air p.r e s s ute rea din gsa r e wit h he ads
loaded at cylinder 0.
60 Hz - .15 or less, replace filter.
50 Hz - .10 or less, replace filter.

Check the RM Adapter and drive power supplies for proper
voltage and ripple levels. Replace any adjustable power
supply if the voltage is grossly out of tolerance instead
of adj usting it back to normal level.
See para. 14.0.
and Table 3-1.

3. 1

POWER ON PR,OBLEMS

3.1.1

CBl Trips
AlQl, AIQ5
Blower Motor
Time Meter
AICl, AIC2 - CAUTION:
YEN, YFN
CRI-CR4
Tl, T2
eBI

3.1.2

Capacitors charged

CB2 Trips
AlQl, AIQ5
T3
CB2

3.1.2.1

Short In +29Y Distribution
K6, K7,

1<8

YFN, YEN
3.1.3

CB3 Trips

3.1.3.1

When CBl Is Turned On
AIQ2, AIQ3
Immediately After The Start Switch Is Turned On
Parking B-rake
Motor

3.1.3.3

Shortly After Motor
Noise Is Heard

Starts

Turning

Belt Tension
Shortly After Motor Starts Turning
Belt Tension
Motor
CB4 Trips
Carriage Lock Pin
Head Load Switch Bad Or Misadjusted
A17
Servo Po we r Amp
K7
Voice Coil Assembly
.22uf Capacitor at TB6 Pins 7 & B
CB4
3.1.5

CBS OR CB6 Trips
5 Volt Regulator
Module
Servo Preamp
YFN
Control Panel (CBS only)
CBS or CB6

3.1.6

CB7 Trips
Module A10, A14, AlS, A16, A17, AlB
A2 Backplane short

_3.1.7

CBB Trips

E"1
A2 Backplane short
CBB

Also

Squealing

~~.1.8

All DC Vol tages Missing At ~rest Points and No +20Y
CB2 Tripped - See para 3.1.2
YEN
A1Q1
CBS or CB6 bad - interlock contacts
T3
+20Y may be loaded down but CB2
Paragraph 3.1.2.1

3.1.9

not

tripped

see

+28V, -20V, +20V, -9.7V, +9.7V Are Either All High or Low
AC input
A1C2 - CAUTION: Capacitor charged
T2

:3 .1.10

-46V, +46V I~ND -16V Are All Ei ther High or Low
AC input
A1C1
T1

3.1.11

-46V, +46V, AND -16V Are Missing
A1QS
YFN
-9.7V missing

3.1.12

Ripple Too High For Just One Voltage
YEN for all DC voltages except -16V
YFN for just -16V

3.2

DRIVE MOTOR PROBLEMS

3.2.1

Drive Motor Starts When CBl Is Turned On
A08
YFN
Start Switch

3.2.2
3.2.2.1

Drive Motor Does Not Turn When Start Switch Is Pressed
+21Y Missing At Pin 3 of AIQ2, AIQ3, AIQ4, AND 9.7V Is
OJ(

YFN
A08

3.2.2.2

+28Y OK At
Missing

3 of A1Q2,

A1Q3,

A1Q4,

and

9. 7V

YEN
CBE
T2
3".2.2.3

+28Y OK At Pin 3 of A1Q2, A1Q3, A1Q4, and 298+ VAC Is OK
At Pin 2
K8

Motor overheated or bad
3.2.2.4

+29Y OK At Pin 3 of A1Q2, A1Q3, A1Q4, but 208+ VAC Is
Missing Pin 2
AIQ2, AIQ3, AIQ4

3.2.3

Motor Overheats and Thermal Cutout Activates
AIQ4
Motor

TABLE 3-1
DRIVE POWER SUPPLY LEVELS
Measure while the drive is performing 128 cylinder con tin U 0 U 5
seeks. Connect meter to power supply test points and be sure to
use Ground T.P.
Voltage

Tolerance

+46
-46
+9.7
-9.7
+20
-20
+28

-2, +5
+2, -5
+/- 1
+/- 1
+/- 2
+/- 2
-/+ 2

The 5 volts is checked also with the 128
cylinder seeks but the test points are
at the backplane.
+5
-5

A2JD94-94A
A2JD94-01A

+/- .95 volts
+/- .95 volts

RM ADAPTER VOLTAGE LEVELS
Voltage

Test Point

+5V
-15V

Pin AA2
Pin AB2

Toleranc~

+4.9 to +5.2
-14.8 to -15.3

TABLE 3-2
Triacs 01, 02, 03, 04, 05 out of circuit readirtgs.
Terminal

3.3

Reading

+
3

•• _> 4

25 Ohms (Forward bias)

+
4

.• _> 3

1 K Ohms (Reverse bias)

--> 2

Infinity

. --> 1 or 2

Infinity

POWER ON AND MOTOR SEOUENCE VDE DRIVES

This section concerns from the time CB1 is turned on, the start
swi tch is pressed 11 and the dr ive motor comes up to speed. The
success of troubl~:~shooting power on problems is dependent upon
thorough and careful visual observations. A general inspection of
all areas is in order for any power or motor problems.
1.

Check all circuit
CB6, CB7, and CB8.

Check for blower motor operation.
Inspect the primary
air filter at the bottom of the drive for need of
cleaning and also check the absolute filter air pressure.
If the air pressure is low, check for air leaks and/or
replace t.hhe filter.
Air pressure readings are with
heads loaded at cylinger 0.
6~
5~

Hz Hz -

break~rs

CB1, CB2,

CB3,

CB4,

CBS,

.15 or less, replace filter.
.1~ or less, replace filter.

Check the RM Adapter and drive power supplies for proper
voltage and ripple levels. Replace any adjustable power
supply if the voltage is grossly out of tolerance instead
of adjusting it back to normal level. See paragraph 14.0
and Table 3-3.

3.4

POWER ON PROBLEMS

3.4.1

CBl Trips
Blower Motor
Time Meter
Cl - Caution:
FCFN Module
TI-T2
CBl

3.4.2

Capacitor charged

C82 Trips
Tl
FeFN Modules
CB2
Short in +28Y Distribution
Kl
CFNN

3.4.3

C83 Trips
Eel
A2 backplane short
CB3
When CBl Is Turned On
Relay box
Immediately After Start Switch Is Turned On
FCNN Module
CFNN Module
Voice Coil Assembly
CB4

3.4.4.3

Shortly After Motor
Noise is Heard

Starts

Turning

Belt tension
3.4.4.4

Shortly After Motor Starts Turning
Belt tension
Motor/brake assembly

Also

A Squeal ing

3.4.5

CBS Trips
CFNN module
Carriage locking pin
Voice coil assembly
K2 on CFNN module
CB6 or CB7 Trips
5 volt regulator module
CCBN module
CB6 or CB7

3.4.7

CB8 Trips
Module Ale, A14, AlS, A16, ~17, Al8
A2 backplane short

3.4.8

All DC Votalges Missing and no +2ey
T2
FI-F8
CCBN module
FCFN module
Auxiliary circuit
Breakers CB3, CB6, CB7, CB8
Tl
CB2

3.4.9

+28v, +29v, -2ev, -9.7v, Are Either All High or Low
T2
CCBN mod ul e·

3.4.18

-46v and +46v Are Both High or Low
T2
CCBN mocule (CRl, CR2, CRS, CRle)

3.4.11

-46v and +46v Missing
CCBN module (CRl, CR2, CR9, CRIe)
46" AC input

3.4.12

Ripple Too High for Just one Voltage
CCBN Module

3.5

DRIVE MOTOR PROBLEMS

3.5.1

Drive Motor Starts When CBl is Turned On
A98 module
Relay box
Start switch

3.5.2
3.5.2.1

Drive Motor· Does not Turn When Start Switch is Pressed
+21Y is OK but 9.7v is Missing
CFNN module
A98

3.5.2.2

+29Y is OK But 9.7v is Missing
CCBN module
CB6 or CB7

3.5.2.3

+20Y is OK and 298 VAC is OK
K3 in relay box
Motor/brake overheating or bad

3.5.2.4

Motor Overheats and Termal Cutout Activates
Relay box
Motor/brake assembly

3.6

DRIVE POWER SUPPLY LEVELS

The drive power supply voltage levels are measured while the drive
is performing 128 cyl inder continuous seeks.
Connect meter to
power supply test points and be sure to use ground test
point. Refer to table 3-3 for voltage tolerances.
The 5 volts is also checked while the drive is perfolC'ming 128
cylinder continuous seeks.
The test points are on the logic
chassis backplane. Refer to Table 3-4.
Table 3-3
Voltage

Tolerance

+46
-46
+9.7
-9.7
+29
-29
+28

-2v, +Sv
+2v, +5v
+lv
+lv
+2v
+2v
+2v

Table 3-4
Voltage

Test Point

+.05 volts
+.05 volts

A2JD94-04A
A2JD94-0lA

+5v
-5v
3.7

Tolerance

PEAK TO PEAK RIPPLE

The peak to peak ripple should be checked using an oscilloscope to
measure the ripple peak to peak ripple voltage between the ground
jack and voltage test jacks on the power supply control panel.
Refer to Table 3-5 for peak to peak ripple voltage.
Table 3-5

3.8

Voltage

Ripple

+46
-46
+20
-20
+28

4.5v
4.5v
1.0v
1.0v
1.0v

RM ADAPTER VOLTAGE LEVELS

The RM adapter voltage levels should also be checked, and adjusted
if out of tolerance. Refer to Table 3-6 for voltage, test points,
and tolerance.
Table 3-6
Voltage

Test Point

Tolerance

+Sv
-lSv

Pin AA2
Pin AB2

+4.9v to +5.2v
-14.8v to -l5.3v

4.9

HEAD LOAD SEQUENCE PROBLEMS

This section concerns problems during the actual head load
operation after the start switch is pressed and the motor is up to
speed.
It also includes the head unload sequence and spindle
braking. If the possible causes are different for NON-VDE and VDE
they will be called out.
4.1

HEADS DO NOT LOAD AFTER
REVERSE CURRENT

4. 2

UP TO SPEED TIME

OUT AND NO

NON-VDE

VDE

Head Load Swi tch
Servo Power Amp
K7
Voice Coil

Head Load Swi tc h
Servo Power Amp
Voice Coil

HEADS DO NOT LOAD AFTER UP TO SPEED TIME OUT AND HOLD
REVERSE IS OK, FOR BOTH NON-VDE AND VDE DRIVES
A20, A07, A12, A08, Al7
Servo Power Amp

4.3

CARRIAGE HITS FORWARD STOP, CB4 TRIPS, FAULT LIGHT ON, AND
HEADS STAY OUT ON PACK, FOR BOTH NON-VDE AND VDE DRIVES
A06, Al9, A20
Servo Power Amp

4.4

CARRIAGE HITS FORWARD STOP, FAULT LIGHT ON, THEN CB4 TRIPS
AND HEADS RETRACT, FOR BOTH NON-VDE AND VDE DRIVES
A2((J
Servo Power Amp

4.5

HEADS LOAD, HESITATES, AND THEN CREEP TO THE FORWARD EOT
(INNER GUARD BAND), FOR BOTH NON-VDE AND VDE DRIVES
A((J6, Al9, A20
Servo Power Amp

4.6

HEADS LOAD, BUT THEN UNLOAD,
NON-VDE AND VDE DRIVES

FAULT LIGHT ON,

FOR BOTH

Servo Preamp *
Servo Head
*
Disconnect A3TBI-I (yellow wire) and load heads manually.
Then Check for .3 -1.5vpp servo data at A18 Pins 23B and
25B. If not OK it is the Servo Preamp or Servo Head. If
OK, it is one of the following.
A18, Al9, A2((J
24

4.7

RTZ IS NON FUNCTIONAL, POR BOTH NON-VDE AND VDE DRIVES
A96, A07, Al9, A29, A02, A12

4.8

UNABLE TO ,sEEK TO CLYINDER 1466 (8), POR BOTH NON-VDE AND
VDE DRIVES
A96, A12, A20, A02

4.9

UNABLE TO FORCE A SEEK ERROR WITH FTU TO CYLINDER 1467
(8), FOR BOTH NON-VDE AND VDE DRIVES
A06, A12, A20 ,A02

4.19

BEADS DO NOT UNLOAD WHEN START SWITCH IS TURNED OFF, START
LIGHT OFF, PACK SPINNING, POR BOTH NON-VDE AND VDE DRIVES
A08, A07, A20, A17
Start Switch
YFN

4.11

DRIVE MOTOn BRAKE INOPERATIVE, NON-VDE DRIVE ONLY
Open thermal resistor in CB3
K8
CR1-CR4
Bad connection to motor connector P/J7

4.12

DRIVE MOTOR BRAKE INOPERATJrVE, VDE DRIVE ONLY
FeFN ModulE~
CCBN Module
Bad Connection to Brake P8/J8
Bad Connection to Motor P7/J7

5.0

POWER AND POWER FAIL PROBLEMS/RM ADAPTER

Oi sk dr ives are susceptable to power problems due to the low level
amplitude analog signals used in the Read/Write circuit.ry.
Any
abnormal variations in the input power such as mismatched phase
loading, vol tage spikes, excessive surges or sags should be corrected immediately before any intermittent failures occur. Typical
failures from abnormal line power have symptoms of long term data
base corruption with no apparent error bit indications and fre'quent power supply related failures.
5.1

MASSFAIL

This signal is sent to all drives on the MASSBUS from their
respective RH controller to indicate a power problem in the RH or
the CPU. Under normal operation the system will power fail as the
Massfail signal is received.
Massfail provides an orderly shut
down of the disk subsystem.
Non Exlstant Drive errors will be
evident if there is a problem with the Massfail signal on the
MASSBUS or in the RM Adapter.
RH7~

- Any Unibus device that generates AC Lo could be at fault.

RH78~ - Check the +5 volt DC Lo signal at J3 of the
supply (#5).

7l~~

power

NOTE
In order to have the Massfail signal
function properly, the jumpers on the
older 8780 MASSBUS terminator modules
must be configured correctly: WI in, W2
out.
5.2

AC LO - UNSAFE, BIT 14 OF RMERl

The RM Adapter -15 volt regulator asserts AC Lo, which sets
Unsafe, if low AC is detected for the RM Adapter power source.
NOTE
If the fault lite is not on in the drive
and the unsafe bit is set, then the
proble. is wi th the RM adapter power
supply.
5.3

DC LO

DC Lo does not flag an error bit but, does give an obvious
indication.
All the RM Adapter registers are read as ones when
examined but the RH registers are OK except for CS1.

6.g

ERROR BITS - CONTROL AND ERROR REGISTERS

This section gives the error definition with suggested ~iagnostics
to use for trouble-·shooting. Also given are the components which
would cause the er~or and/or symptom.
When trying to locate a problem, it is assumed that the error and
status logic is functioning properly. The list of possible
defective components are listed in order of most likely to fail
first and easiest to replace. These component listings are given
to start you off in the right area but test equipment such as
8 scope and meter ~,ill be needed to isolate further.
The status
and error logic should be, for most cases, considered last unless
it is obvious.
STATUS AND ERROR LOGIC INCLUDES
1.
2.
3.

Drive Interface Cables - A & B
M7686 - drive status, drive errors
A0l, A02, A17 - drive status, drive errors

Multiple bits will be set when an error occurs. EXAMPLE: A
parity error occurred. Bit 03 (PAR) of RMERI and bit 03 (DPE) of
RMER2 is set; bit 15 (ATA) and bit 14 (ERR) of RMDS; corresponding
bit in RMAS; bit 15 (SC) and bit 14 (TRE) of RMCSI.
Be aware of
all bits when isolating an error condition.
Table 6-1 gives related FTU errors to subsystem errors. This can
be used to relate the Error Log or Diagnostic printouts to errors
when troubleshooting with the FTU.
Table 6-1
RM ADAPTER ERROR

FTU ERROR

ILF

ILR

RMR

PAR

FER & HCRC

Address and/or Read

FER

WCF

ECH & DCK

Address and/or Read

HCE

Address - because of head misselect SKI
and/or Address because of misposition
27

Table 6-1 (Cont)
RM

ADAPTER ERROR

FTU ERROR

HCE & HCRC

Address and/or Read

HCRC

Address and/or Read

AOE

IAE

WLE

Fault

DTE

Read after write Address error, Address
and/or Read

OPI

Sector Count or no error

UNS & DVC

Fault

DCK

Address and/or Read

DPE

DVC

Fault

LBC

Address and/or Read FTU Run hangs

LSC

IVC

No Uni t Ready

OPE

Plug No. doesn't equal switches
No Un it Select

SKI

SKI Address

BSE & HCRC

Address and/or Read

6.1

CONTROL REGISTER

6.1.1

Control Register
BIT 13
BIT 17

MASSBUS CONTROL PARITY ERROR (MCPE)

- :RH70
- RH780

MCPE indicates that a parity error occurred on the Control
Bus while read ing an RM reg ister to the RH. ThelC'e is one
RM Reg ister that does not use par i ty on transfer to the
RH. It is the Attention Register.

THINGS TO KNOW WHEN TROUBLESHOOTING MCPE ERRORS
1.

The number one cause of MASSBUS Parity Errors (especially
on installations) seems tC) be in the cabling. Check the
following:
o

Check the connections of the BC06R cables at the
M5904's' RH70 (Berg connector). The drain wire on the
flat cable sometimes shorts against the etch on the
M5904. This effects Data Bits 00, 06, or 12.

Check the connections of BC06R cables at the ZIF
(Zero Insertion Force) connector located on the panel
on the bottom rear of the cabinet.

Visually inspect the cable insulation on the BC06R
cables for damage, kinks, breaks and other signs of
wear.

A visual inspection of all ZIF connector mating pins
is necessary.

Inspect the massbus terminator for bent pins, and
broken or cracked resistor packs.
MASSBUS terminators which have broken or cracked resistor packs will
give intermittant parity errors.

To isolate solid MCPE problems,
features that will help out.

there

are

several

The maintenance switches on the M5922 and M5923 will
disable all transceivers on that bus, for that drive.

In multiple RM05 installations, break the MASSBUS and
move the terminator in order to isolate the problem.
Remember, the MASSBUS must be terminated at all
times" and at least one dr ive enabled on the bus,
otherwise, erroneous parity errors will occur to
non-e,cistant drives.
Use the MASSBUS TDR Tester to
isolate.

If an eight drive system is in use, the first four
drives will operate properly, but the last four
drives will fail intermittently. This is due to the
MASSBUS load of the last dr ives.
The first four
drives will see the load as a terminator.

MASSBUS Cable Length Specification
The MASSBUS
specification clearly states that the maximum lengths for
the flat (BC06R-XX) and round (BC06S-SS) cables are 120
feet and 160 feet, respectively.
A linear interpolation
must be llsed for mixed flat and round cable systems to
calculate the maximum length. See the MASSBUS TDR Tester
Manual.
29

Diagnostics
11/70
CZRMP Diskless
CZRMQ Diskless 2
CZRMU Performance Exerciser

VAX
EVRDA Diskless
EVRAA Reliability

Drive
Not Drive Caused

RM Adapter
Terminator or Jumpers (Wl and W2)
Cables
M5922, M5923
Grounds
M7686

RH70

RH780
M8278
M9041

~es

M5994
M8152

If TRE is not set and no errors are present or attention is set
for no reason.
RH70
M81S1
MS904

(B)

6.1.2

Control Register

RH780
M8278

BIT 14

TRANSFER ERROR (TRE)

TRE indicates that an error occurred in either the RH
controller or the Disk Drive. This error condition is the
OR-ing of DLT, WCE, PE, NED, NEM, PGE, MXF, MDPE or an
error bit in one or a combination of all three drive error
registers.
6.1.3

Control Register
BIT 15

SPECIAL CONDITION (SC)

SC indicates that an error condition exists thru the TRE
bit being set by MCPE. Also attention will set SC because
of a normal condition such as the drive cloming on line,
or the completion of a positioning command. SC could set
for either a normal or abnormal condition, it is just a
flag for something happened.
Diagnostics

Depending
on
the
error
condition, all including DECXll

DRIVE
Normally or abnormally the drive going on or offline. will set SC
thru the attention bit. Check for error conditions.
RM ADAPTER
Check for error bi ts.
If none set these modules may cause the
problem if attention is set.
M7686
MS922, MS923
Diagnostic

All including DECXll

Drive

RM Adapter

Check the error registers and
section of this manual.

refer to the specific error bit

If no errors are present
RH70
M81S1
M81S0

RH780
M8278

If TRE is not set. and no errors are present or attention is set
for no reason.
RH70
M81S1
MS904

RH780
M8278
(B)

6.2

STATUS REGISTER

6.2.1

Status Register
BIT.88
BIT 88

MASSBUS DATA PARITY ERROR (MDPE)

- RH70
- RH780

An MOPE indicates a parity error was detected on the
synchronous (data) bus lines during a read type data
command.
(Read, Read Header and Data, Wr i te Check or
Write Check Header and Data). The error could be caused
anywhere :from the RM Adapter to the RH.
THINGS TO KNOW WHEN TROUBLESHOOTING MDPE ERRORS
1.

The number one cause of MASSBUS Parity Errors (especially
on installations) seems to be in the cabling. Check the
following:

Check the connections of the BC06R cables at the
M5904's RH70 (Berg connector). The drain wire on the
flat cable sometimes shorts against the etch on the
M5904. This effects Data Bits 00, 06, or 12.

Check the connections of BC06R cables at the ZIF
(Zero Insertion Force) connector located on the panel
on the bottom rear of the cabinet.

Visually inspect the cable insulation on the BC06R
cables for damage, kinks, breaks and other signs of
wear.

A visual inspection of all ZIF connector mating pins.

Inspect the MASSBUS terminator for bent p:lns, and
broken or
cracked
resistor
packs.
MASSBUS
terninators which have broken or cracked resistor
packs will give intermittent parity errors.

To isolate solid MOPE problems,
features that will help out.

there

are

several

The maintenance switches on the M5922 and M5923 will
disable all transceivers on that bus, for that drive.

In multiple RM05 installations, break the MASSBUS and
move the terminator in order to isolate the problem.
Remember, the MASSBUS must be terminated at all
times, and at least one dr ive enabled on the bus,
otherwise, erroneous parity .errors will occur to
non-existent drives.
Also use the MASSBUS TOR
Tester.

If an eight drive system is in use, the first four
drives will operate properly, but the last four
drives will fail intermittently. This is due to the
MASSBUS load of the last drives. The first four will
see the load as a terminator.

MASSBUS Cable Length Specification
The MASSBUS
specification clearly states that the maximum lengths for
the flat (BC06R-XX) and round (BC06S-XX) cables are 120
feet and 160 feet, respectively.
A linear interpolation
must be used for mixed flat and round cable systems to
calculate the maximum length. See the MASSBUS TDR Tester
Manual.

Diagnostics
11/70
CZRMQ Diskless 2
CZRMN Functional 2,
CZRMO Functional 3
CZRMU Performance Exerciser

VAX
!VfiDA Diskless
EVRDB Functional
EVRAA Reliability

Drive

DeL

~les

M7685
M5922, M5923

RH70
CaE'res

RH780
MS·277

M5904
M8l50

M904l

6.2.2

Status Register
BIT 99

MISSED TRANSFER (MXF)

MXF indicates that the drive did not respond to a data
transfer command wi thin 650 msec for an RH70.
Basicall y
what happens is three condi tions may cause this error
condition. The first one being that the RH decoded a Data
transfer command and the RM Adapter did not decode it or
respond to it by sending "Occupied" back to the RH via the
MASSBUS.
The second reason is that "EBL" from the RM Adapter via
the MASSBUJS was not rece i ved in the RH at the end of the
sector wi th the word counter cleared (run cleared).
The
best thing to do is scope for "Occupied" or "EBL" if no
other Diagnostics errors are present.
It is possible to
get MXF errors with other error conditions.
The thi rd reason is that in an eight dr ive system, the
first four drives will operate properly, but the last four
drives will fail intermittently.
The reason being is
because of the MASSBUS load of the last drives. The first
four drives will see the load as a terminator. Also check
the MASSBUS terminator for broken or cracked resistor
packs.
This will give you intermittent parity errors in
addition to a missed transfer error.
Diagnostics
11/70
CZRMQ Diskless 2
CZRMN Functional 2
CZRMO Functional 3
CZRMU Performance

VAX
!V'R"DA Diskless
EVRDB Functional
EVRAA Reliability
33

Drive
Not Drive Caused

RM Adapter
ItlXSSBOS Cable
MS922, MS923
M7686
M7684

RH70
CaDre
MS604-B or C
M81S1

RH780

6.2.3

M8278

M8277
M9041

Status Register
Bit 18

PROGRAM ERROR (PGE)

PGE indicates for the RH70 & RH7S0 that software attempted
to initiate a data transfer operation while currently
performing one.
In addition for the RH780, the program
tr ied to load, MAP, VAR, or byte counter, or set
maintenance mode during a data transfer command. Also for
the RH7S0 an attempt to initiate a unacceptable data
transfer command.
Diagnostics
11/70
CZRMQ Diskless 2
CZRMN Functional 2
CZRMO Functional 3

VAX
EVRDA Diskless
EVRDB Functional
EVRAA Reliability

Drive
Not a Drive Problem
RH70
MSISl
6.2.4

RH780
M8278
M8276
Status Register
Bit 11

NON EXISTANT MEMORY (NEM)

NEM sets when the controller is performing a DMA transfer
and the memory address specified in the Bus address
register is non-existent.
This problem can be caused by:
1.

Software

Defective Memory Stack

Hardware problem with the Bus Address Register or error
detection logic.
34

Diagnostics
VAX

11/7~

DECEX 11
RH70
MS151
MS152
6.2.5

RH780

MS276

M8275

Status Register
BIT 12
BIT 18

NON EXISTENT DRIVE (NED)

RH70
RH780

NED Sets when a program reads or writes a drive register
in a drive which does not exist or is .powered down.
Essentially what happens is that the RH did not received
"Transfer" on the MASSBUS 1.5 Usee after "Demand" was
transmi ttfed over the MASSBUS from the RH. Several things
could cause NED.
1.

Mass Fail is asserted.

See para. 5.1

Drives are disabled by the enable switch on the M5922 or
M5923.

Drive select lines or Logic is defective.

MASSBUS failure of "Demand" and or "Transfer" in the RH,
RM Adapter, or MASSBUS cabling.

DEV Selected neg~ted in RM Adapter.

Diagnostics
11/70
CZRMP

Diskless 1

Drive
Power on?

RH70
ra"6les
M5904 (C)
MS151
MS153

VAX
ERVDA Diskless
RM Adapter
Adapter not powered on
MASSBUS cables
M7686
M5922, M5923

RH780
A8278
M8276

Status Register
BIT 13

PARITY ERROR (PE)

PE indicates a parity error from memory is detect~~d while
the controller is performing a Write or Writ.e-Check
command.
Diagnostics
DECXll
Drive
Not a Drive Problem
RH7e

M8T52
M81Sl
6.2.7

Status Register
BIT 14
WRITE CHECK ERROR (WCE)
BIT "9 & 1"

- RH70
- RH780

weE sets when the controller is performing a write check
operation and a word on the disk does not match the
corresponding word in memory.
The thing to be aware of on troubleshooting WCE' s is the
s tat us 0 f the d a t a c h e c k err 0 r bit.
If Da taCh e c k i s s e t
with weE set, the word on the Disk itself was read
inc 0 r r e c t 1 Y• In 0 the 'r wo r d s, ig nor e th e WC E •
If weE is set alone one of two things happen.
Data was
changed on the parallel transfer to the RM Adapter or the
Data was changed from the RM Adapter to memory.
Areas that could cause WCE.
1.

MASSBUS - if an even number of bi ts were effected since
parity would not detect this problem.

Data Transce iver in RH.

Incorrect Data Patterns on Pack when running Performance
Exerciser.

NPR timing is bad. - 11/70

Diagnostics
11/70

CZRMQ Diskless 2
CZRMN Functional 2
CZRMNO Functional 3
CZRMU Performance Exerciser
Drive
Could be if DCR set

VAX
!VIrDA Diskless
EVRDB Functional
EVRAA Reliability
RM Adapter
M7685
M5922, M5923

Cables
RH70
M81S0
MS904

RH780
M8277
M8275

Cables

The processor could also cause WCE.
6.2.8

Status Register
BIT 15

DATA LATE ERROR (DLT)

BIT 11

- RH70
- RH780

DLT Sets when the controller is unable to supply a data
word during a write operation or accept a data word during
a read/write check operation at the time the drive demands
a transfer.
Usually DLT indicates a severely overloaded Bus
hardware problems with "Sync Clk" can also cause
error.
Diagnostics
11/70

CZRMN Functional 2
CZRMO Functional 3
CZRMU Performance Exerciser
DECEX 11
Drive
Not Drive Caused

VAX
I\m'DB Functional
EVRAA Reliability

RM Adapter
A"7685
M5922, M5923

RH70

RH780
M8277
M8276
M9041

R'ITS"1
M8150
6.3

ERROR REGISTER 1

but
the

6.3.1

Error Register 1
BIT I I

ILLEGAL FUNCTION (ILF)

ILF ind icates that an invalid function code was loaded
into the control register (CSI). It is possible for the
control bus to cause this error but usually bit 03 (parity
error) of RMERl will show up intermittently by itself.
Diagnostic
11/70

VAX

CZRMP Diskless 1

!VR'DA Diskless
EVRDA Diskless

Drive
Not Drive Caused

RM Adapter
M7686

Software
See Parity Error
6.3.2

Error Register 1
BIT 81

ILLEGAL REGISTER (ILR)

ILR indicates a register address greater than 17 was
selected.
Normally a software flag-but several logic
faul ts-can cause the error.
They are the error detect,
RH, and MASSBUS logic.
Diagnostics
11/70

VAX

CZRMQ Diskless 1
CZRMQ Diskless 2

!'mDA Diskless

Drive
Not Drive Caused

RM Adapter
M7686
M5922, M5923

Terminator
RH70
M'S904
6.3.3

RH780
M8278
M904l

Error Register 1
BIT 12

RMR indicates that an attempt was made to write a
register, except the Attention Summary and Maintenance
Register, when the -GO- bit was set.
38

Diagnostics
11/70
CZRMP Diskless 1

VAX

'!'\m"DA Diskless

Drive
Not Drive Caused

RM Adapter
Wi686
M5922, M5923

RH70

RH780
M8278

Jf5904
6.3.4

Error Register 1
BIT 03

PARITY ERROR (PAR)

PAR indicates a Parity error occurred while writing into
an RM register or when Bit 03 (DPE) of RMER2 is set.
Normally indicates even parity was detected on the Control
Bus lines or that even parity was detected on the Data Bus
if Bit 03 (DPE) of RMER2 is set.
Diagnsotics
11/70
CZRMP Diskless 1
CZRMQ Diskless 2
CZRMM Functional 1
CZRMN Functional 2
CZRMO Functional 3
CZRMU Performance Exerciser

VAX

Drive
Not Drive Caused

RM Adapter
COntrol Bus - M7686
M5922, M5923
Cables
Terminator

EVRDA Diskless
EVRDB Functional
EVRAA Reliability

Data Bus - See bit 03 of RMER2
RH70
M5904
M8152
6.3.5

Rli780
Cables
M8278
Error Reg:lster 1
BIT 04

FORMAT ERROR (FER)

FER normally indicates that the wrong pack format is being
used or t,he software did not condition the Format Bit in
RMOF.

Abnormally it means bit 12 of the first header word was
dropped but HCRC will indicate this.
If HCRC is set,
isolate the problem as a read error. See OCK •.
Diagnostics
11/70
CZRMP Diskless 1
CZRMQ Diskless 2
CZRML Format
CZRMM Functional 1
CZRMN Functional 2
CZRMO Functional 3
Drive
Pack Format
If caused by a read
see DCK
6.3.6

VAX
IVR'DA Diskless
EVRDB Functional
EVRAA Reliability

RM Adapter

M1685
M7686

Error Register 1

BIT 05

WRITE CLOCK FAILURE (WCF)

WCF indicates, during a Write Header & Data or Write Data
command, that the MASSBUS signal "Wr i te Clock" was not
received at the RM adapter after a "Sync Clock" \~as sent
to the RH from the RM.
Diagnostics
11/70
CZRMQ Diskless 2
CZRMN Functional 2
CZRMO Functional 3
CZRMU Performance Exerciser

VAX
!V'R'DA Diskless
EVRDB Functional
EVRAA Reliability

Drive
Not Dr ive Caused

RM Adapter
M7686
M5922, M5923

RH70
M5904 - C

RH780
M8277
M9041

6.3.7

Error Register 1

BIT 06

ERROR CORRECTION HARD (ECH)

ECH indicates, at the end of an error correction, a
non-ECC correctable error. Normally set with Bit 15 (DCK)
of RMER1 during a uncorrectab1e ECC error.
ECH should
never be set without DCK. See DCK.

Diagnostics
11/70
CZRMP Diskless 1
CZRMQ Diskless 2

IVR"DA Diskless

Drive
EcR alone not drive
caused. See DCK

RM Adapter
A"7685
M7686

6.3.8

VAX

Error Register 1
BIT 07

HEADER COMPARE ERROR (HCE)

HeE indicates, without HeRC,
three mis-compares occurred.

FME,

BSE,

that one of

NOTE
Head crash may also be a cause of HeE
errors.
1.

The Cylinder Address register and the first header word
are not equal indicating:
a.

Servo mis-position - this is usually associated with
SKI errors.

Incorrect pack format

Logic failure - RM Adapter

The Track Address register and the track address portion
of the second header are not equal indicating:
a.
b.
c.
d.

Head mis-selection - Drive logic
Incorrect pack format
Head plugs switched
Logic failure - RM Adapter

The Sector Address register and the sector address
portion of the second header word are not equal
indicating:
a.
b.

Incorrect pack format
Logic failure - RM adapter

Diagnostics
11/70
CZRMP Diskless 1
CZRMQ Diskless
CZRMV Extended Drive
CZRMU Performance *
* Gives header info on HeE's.

VAX

!VR'DA Diskless
EVRDB Functional

Drive
RM Adapter
MIS-POSITION
M7684
Servo adjustment
A12, A~8, A2~, A~7
A19, A18, A92, A~6
Servo Preamp
Servo Power Amp·
Velocity Transducer
Servo Head/Servo Head Crash
Carriage Way Bearings
Arcing Coil or Flex Strip
HEAD MIS-SELECT
A~2,
E~5

A~l,

M7684

A~8

Head Plugs Switched
SECTOR MIS-SELECT
A~6,

A1~,

A~l,

A~2

May be associated with
OPI and DTE Errors.
NO MIS-COMPARES

6.3.9

M7684
M7685
M7684
M7685
M7686

Error Register 1
BIT 98

HEADER CRC (HCRC)

HeRe indicates a read error in the header.
When a
compared bit is picked or dropped; HCE, BSE, or FER may be
set. When an uncompared bit is picked, just HCRe will be
set.
If solid HCRC's are present or intermittent HCRC
without; HCE, BSE, OR FER, the CRC logic is chief suspect.
HeRC set wi th the other header er ror bi ts and random DCK
indicates a problem with the read logic. See DCK.
Diagnostics
11/7~

CZRMP Diskless 1
CZRMQ Diskless 2
CZRMM Functional 1
CZRMN Functional 2
CZRMO Functional 3
CZRMV Performance*
*SWR = 3; Size - 156
Drive
See DCK

VAX
EVRDA Diskless
EVRDB Functional
EVRAA Reliability

RM Adapter
M7685
M7686

6.3.18

Error Register 1
BIT 99

ADDRESS OVERFLOW ERROR (AOE)

AOE ind icates that a data transfer was requested beyond
the last address of the pack - CYL 822, TRK 18, SECT 31.
This occurs when the word count register large enough to
cause a mid transfer seek beyond the last block.
LBT of
RMDS will also be set.
Diagnostics
11/70

CZRMP Diskless 1
CZRMQ Diskless 2
CZRMN Functional 2
CZRMV Performance
Drive
Not Drive Caused

VAX
!VTfDA Diskless
EVROB Functional
EVRAA Reliability
RM Adapter

M1685
M7686

Software
operating Software
6.3.11

Error Register 1
BIT 10

ILLEGAL ADDRESS ERROR (IAE)

IAE i nd i ca tes that a val ue beyond the max imum RM05
Cylinder or Sector/Track address spectrum was written into
either register and was flagged when the "Go" bit was set.
Diagnostic
11/70

CZRMP Diskless 1
CZRMQ Diskless 2
CZRMM Functional 1
CZRMN Functional 2
CZRMN Functional 2
Drive
Not Drive Caused

VAX
EVRDA Diskless
EVRDB Functional

RM Adapter

J.r7685
M7686

Software
Operating Software
SEE PARITY ERROR - 6.3.4

6.3.12

Error Register I
BIT 11

WRITE LOCK ERROR (WLE)

WLE ind icates that a wr i te command was issued to a wr i te
locked drive.
Diagnostics
11/70
CZRMP Diskless 1
CZRMP Diskless 2
CZRMM Functional 1
CZRMN Functional 2
Drive
A01, A09
Write Lock Switch
6.3.13

VAX
EVRDA Diskless
EVRDe Functional

RM Adapter

M7684

M7686
Operator Error

Error Register 1
BIT 12

DRIVE TIMING (DTE)

DTE indicates more than one Sector Pulse occurred within a
sector. This can be attributed to three areas:
1.

Pack formatted incorrectly

Sector pulse generation logic.
with OPI errors. - Drive.

No read data from the drive into the RM Adapter.

Could be one of the first signs of a head crash.

This may be associated

Diagnostics
11/70
CZRMP Diskless 1
CZRMQ Dskless 2
CZRMM Functional 1
CZRMN Functional 2
CZRMO Functional 3
CZRMI Formatter
CZRMU Performance

VAX
EVRDA Diskless
EVRDS Functional
EVRAC Formatter
EVRAA Reliability

Drive
Pack Format
A06, A0l, Ale, A13
A1S, A14, E03, E04
R/W Head if just one
track affected

RM Adapter
M7687
M7684
M7686

6.3.14

Error Register 1
BIT 13

OPERATION INCOMPLETE (OPI)

OPI indicates one of three problems:
1.

No activi ty on the dr ive interface wi thin 399ns after a
seek is initiated by the AM Adapter.

The correct sector is not found in three index pulses The Sector Address register does not equal the Sector
Counter of the drive.

Run is not asserted within 20ms after the -GO- bit is set
for a data transfer command.

Diagnostics
11/70
CZRMP Diskless 1
CZRMQ Diskless 2
CZRMM Functional 1
CZRMN Functional 2
CZRMO Functional 3
CZRMU Performance

VAX
!'VT{DA Diskless
EVRDB Functional
EVRAA Reliability

RM Adapter

Drive
Sector Problem
A06, A10, A01, A02

M7684
M7686

No Drive Interface Activity
A02, A12, A07

M7684
M7686

Run Problem
Not Dr ive Caused
RH70

RH780
M8277
M8276
M9941

M5904
M8152

MASSBUS
Cables
6.3.15

Error Reg:lster 1
BIT 14

UNSAFE (UNS)

UNS indicates that a AC low condi tion exists wi th the RM
Adapter power supply or that the drive has a Device Check
error. See DVC.

Diagnostics
VAX

11/70

All diagnostics

See DVC if set

Drive
Only if DVC is Set
See DVC

RM Adapter
Low AC power input
15 volt regulator
M7686

are applicable

6.3.16

Error Register 1
BIT 15

DATA CHECK ERROR (OCK)

OCR error without ECH indicates that one or more bits were
picked or dropped in the data field within a 11 bit burst.
With ECH, it indicates that more than 11 bits were picked
or dropped in a row, or that two bi ts seperated by more
than 11 bits were picked or dropped.
Also if a bit was
dropped or picked in the ECC field wi 11 set OCI<.
OCK
usually indicates the drive is having a read problem.
Other symptoms of drive read problems and not just ECC
logic faults are; header errors with HCRC set; recoverable
DTE's.

Causes of Read Errors
1.
2.
3.
4.
S.

Read logic in the drive
Write logic in the drive
Servo logic
Pack
EMI noise

A good point to remember when using the performance exerciser
program; is when a data check with or without ECH occurs during a
write check, or write check header and data command, (51 or 52),
with no data compare errors, this strongly indicates a ECC logic
problem which is in the RM Adapter.
When troubleshooting, things to note are where and how erJt'ors are
occurring_
TRACK -

1) All one track but different
matrix, head, or even the pack.

sectors

indicates

2)
All
one
track,
same
sector,
cylinders
consecutively close - indicates scratched pack.
3) Check for head crashes.
HIGH CYLINDERS - indicates read or write problem with drive.

RANDOM CYLINDERS - indicates possible drive problem. but if HeE,
FME, and BSE occur with HCRC this clinches the drive. If no other
errors are present the ECC logic may be at fault.
COMPATIBILITY - if packs are swapped between drives and errors are
on one track head alignment may be required.
Also, if errors
occur only on high and low cylinders, carriage alignment may be
neccessary.
SERVO ERRORS - if SKI errors are present as well as data errors,
tackle the servo error first.
Diagnostics
11/70
'CZRMQ Di skless 2
CZRMN Functional 1
CZRMO Functional 3
CZRMT Compatability
CZRMV Extended Drive
CZRMU Performance
CZRML Formatter
Drive Indicatives:
1. Random, high density
areas.

VAX

~DA

Diskless
EVRDB Functional
EVRAA Reliability
EVRDC Formatter

RM Adapter Indicates:

1. Random without regard to high or
low cylinders
without HCRC.

2. HCRC errors.
3. Surface related - track
4. Carriage ground.

2. No WRT CHK error
wi th OCK er ror
using the diagnostics on a WRT
check command
(51 or 53).

Drive

RM Adapter

Pack

Al4, Al5, Al0
E03, E04, E05,
R/W Head

M7685
M7687
M7686
A&B cables not
grounded

A02, A19, A20 *
Servo Preamp *
Servo Power Amp *
Spindle Ground
Spindle *

* These may be associated with W+R OFF CYL Faults

6.4

ERROR REGISTER 2

6.4.1

Error Register 2
BIT 93

DATA PARITY ERROR (DPE)

DPE indicat"es even parity was detected during a W:rite Data
or Write Data and Header Command. This bit also sets Bit
03 (PAR) of RMERI. Since parity is checked at the output
of the shi ft reg i ster in the RM Adapter, The I)PE could
occur anywhere from the shift register back to the RH.
Diagnostics
11/70
CZRMQ Diskless 2
CZRMN Functional 2
CZRMO Functional 3
CZRMU Performance

VAX
EVRDA Diskless
EVRDB Functional
EVRAA Reliability

Drive
Not Drive Caused

RM Adapter
M7685
M7686

M5922, M5923
Terminator
Cables
6.4.2

Error Register 2
BIT 07

DEVICE CHECK (DVC)

DVC indicates one of six drive fault conditions.
1.

Write Fault
a.
b.
c.
d.
e.

Head winding shorted - replace head.
Write Driver output low.
Input current to Write Driver low.
+22 volts to Write Driver low.
No write transitions with Write Gate asserted.

Head Select Fault"- multiple head select.
head.

Write and Read Fault - simultaneous Write and Read Gate.

ON Cylinder Fault - On Cylinder goes away while reading
or wr i ting.

Voltage Fault
voltage is low.

Servo Fault
No dibits 350ms after
seg uence beg ins. No LED Indicator.

46v,

5v,or

20v

Usually a bad

positive" or
the

negative
head

load

Diagnostics
11/70
'CZRMP Diskless 1
CZRMQ Diskless 2
CZRMM Functional 2
CZRMN Functional 3
CZRMO Extended Drive
CZRMU Performance

VAX
'!VtrDA Diskless
EVRDB Functional
EVRAA Reliability

Drive
:Wr i te Faul t
Al7, A10, A13, A02, A19, A0l
E02, E0l

RM Adapter
M7684
M7686
-lSvolt supply
glitches

Head Select Fault
Al7, E01, E0S, E04 A08
A0l, A02
Write and Read Fault
A17, A02, A19, E0l, A13
A0l, A14, AlS
Cyl W+R Faul t
Pack
A17, A02, A19, E02, A07
A08, A20,
Servo Preamp
Servo Power amp
Spindle
On

6.4.3

Error Register 2
BIT 19

LOSS OF BIT CLOCK (LBC)

LBC indicates that Bit Clock transitions were absent
longer than 400ns.
Bit Clock is derived from Read Clock
and Servo Clock.
Diagnostics
11/70
CZRMP Diskless 1
CZRMQ Diskless 2
CZRMN Functional 2
CZRMO Functional 3
CZRMU Performance
Drive

A01, AlS, A10
Cable

VAX

~DA

Diskless
EVRDB Functional
EVRAA Reliability

RM Adapter
R"1l)S7
M7686

6.4.4

Error Register 2
BIT 11

LOSS OF SYSTEM CLOCK (LSC)

LSC indicates one of two problems.
1.

With the ~Go" Bit reset,
absent longer than 3usecs.

With the "Go" Bit
address changes.

Wi th the "Go" Bi t set and Bi t clock di sappears, LBC and
LSC will both be set.

set,

System
there

clock
an

transition
absence

are
Prom

Diagnostics
11/7"
Same as Loss of Bit Clock

VAX
Same as Loss of Bit Clock

Drive
See LBC if LBC is set.

M7684

6.4.5

RM Adapter

M7686
M7687 if LBC set

Error Register 2
BIT 12

INVALID COMMAND (IVC)

lVC indicates that "Volume Valid" or "Unit Ready" is not
asserted when any command except "Read In Preset" or" Pack
Acknowledge" is attempted.
Diagnostics
11/7"
CZRMP Diskless 1
CZRMQ Diskless 2
CZRMM Functional 1
CZRMN Functional 2

VAX
EVRDA Diskless
EVRDB Functional

Drive
A17, A"l
Cable

RM Adapter
M7684
M7686

6.4.6

Error Register 2
BIT 13

OPERATOR PLUG ERROR (OPE)

OPE indicates the drive address plug is removed.

Diagnostics
11/70
All

XIT

Drive
Address plug removed.
Al?, Cable

RM Adapter
M7684
M7686

VAX

Error Register 2

BIT 14

SEEK INCOMPLETE (SKI)

SKI indicates one of three problems in the servo logic:
1.

The drive is unable to do a seek within S00ms.

The Forward or Reverse EOT's (guard bands) were detected
while heads are supposed to be On Cylinder or while seeks
a re be ing per fo rmed •
EO'I" s could be detected for three
reasons:

A mis-position occurred and the drive was forced to
EOT on the next seek. Related to b. below.

Veloc i ty problem caused an overshoot of the servo
into the EOT. This would occur when seeking close to
cylinders 0 and 822.

Faulty end of travel (EOT) detect logic.

A cylinder address greater than 822 was loaded into the

drive.
This SKI error should not occur unless there is
an interface problem between the drive and the RM Adapter. This is because the RM Adapter would flag an Invalid
Address Error and abort the command before loading a
bogus cylinder address into the drive.
If there were an
interface problem other symptoms would be noticed.
HCE
due to head mis-selection, commands such as Read, Write,
RTZ, improperly funtioning.
This form of SKI could also
be due to faulty error logic.
Diagnostics
11/70
CZRMQ Diskless 2
CZRMN Functional 2
CZRMU Extended
CZRMU Performance

VAX
!'V'R"DA Diskless
EVRDB Functional
EVRAA Reliability

Drive

A0S, A07, A06, A19,

A12, A18, A20, A02
Servo Power Amp
Transducer
Servo Preamp
Servo Head
Binding Carriage Way Bearings
6.4.8

RM Adapter
M7684
M7686

Error Register 2
BIT 15

BAD SECTOR ERROR (BSE)

BSE indicates that bit 14 and or 15 of the first header
word were read as a 0.
Bl t 14 and 15 are wr i tten as a
zero to indicate a bad sector. This error is transparent
to the operating system error log or dur ing diagnostics
because the format programs will flag these bad sectors in
the Bad Sector File. The error will show up during a read
error but HCRC will also be set.
Diagnostics
11/70
CZRMP Diskless 1
CZRMQ Diskless 2
CZRMN Functional 2
CZRMO Functional 3
CZRML Formatter
CZRMU Performance Exerciser
Drive
Not Drive Caused If
No Read Errors. See DCK
If Read Errors Are Present

VAX

~DA

Diskless
EVRDB Functional
EVRDC Formatter
EVRAA Reliability

. RM Adapter
M7685
M7686
M5922, M5923

7.0

BOOTSTRAP PROBLEMS

Bootstrap problems are one of the very common sympto~s expressed
by customers and may indicate any of a variety of problems
throughout the system. Briefly, the bootstrap is a small program
that tells the disk to read (Cyl S, Sector S, head S) 1 block (256
words) into memory. This block contains a program that reads more
programs off the disk into memory 'that forms the Operating System
Moni tor.
The syst:em is then considered ·up" and ready to accept
commands from the customer's operator.
This entire operation
assumes the basic system components (CPU, Memory, System Disk and
Unibus) to be functioning completely. When this operation fails,
there are a few basic steps to follow that should isolate any
hardware problem's:
1.

Halt the CPU (do not hit the start switch which issues a
system Init) and examine the disk registers for any error
bits.
If there are any error bit indications proceed to
the section in this manual for that bit.
If no error
condition exists, examine the 11/7S maintenance registers
or the standard PDPll Memory par i ty reg isters for any
error indications.

Determine if there are~any other disk packs on site that
have a bootable image and try them. Be sure not to use
the "only" customer backup. A diagnostic pack is usually
a good choice (keep it write protected). Also remember
the "Expand" Operating System does not use interruptors
like the customer's software.

If you have a multi-drive system, try to boot the pack on
another drive.
This may determine if you have a
compatib:ility or data base corruption problem (see
appropriate section).

If no other packs are available, try to bootstrap another
device such as a tape unit, Floppy disk, etc.
In order
to run some diagnostics.
Be sure to use the CPU
instruction exerciser, te~t ROM Bootstrap, basic disk
subsystem diagnostics. If no problems are found there is
sti 11 the possibi 1 i ty of device interaction problems on
the Unibus.
DECX-Il should be run to isolate this type
of problem.
If no apparent hardware problem can be found, you must
assume the data on the pack to be corrupted.
Please
refer to the section on Data Base Corruption.

8.g

COMPATIBILITY

Compatibility is the ability to interchange media bet'lI7een like
disk drives and 'read the data on the packs within the error rate
Spec for the drive. Compatibility is made possible by keeping the
mechanical tolerances that are defined by the head a1 ignment and
carriage way procedures.
It is possible to have what seems to be a compatibility problem
between drives but really is an ELECTRICAL PROBLEM due to
misadjustment or a defective component.
8.1

COMPATIBILITY PROBLEMS

Compatibility problems are defined as an inability of a drive to
read data on a pack that was written on a different drive or
drives.
Two distinct areas arise, the data was written
incorrectly (uncommon) or a· drive is reading incorrectly (more
common) •
There are also two data areas in each sector that are
usually recorded on different drives. The header area is recorded
only when the pack is formatted and the data area can be written
at any time the system is in use. It is useful to determine on
which drive the pack was formatted and on how many drives the pack
has been used in order to isolate which drive has a problem.
Please note that each of the two data areas (Header and Data) have
separate error symptoms that are helpful in isolating the failing
drive. Here are some hints on isolating a drive problem:
•

Insure each drive runs the Performance Exerciser (11/70 CZRMU) or Reliability (VAX - EVRAA) diagnostic on a
scratch pack that is formatted on that same drive.
Please note that bad spots mayor may nGt be picked up on
all drives.

•

If on a 11/70, run the Compatability diagnostic (CZRMT).

•

If on a VAX, run Formatter EVRAC and format the fi rst
drive. Then move the pack to the next (or suspect) drive
and run" Read All". Any errors would indicate a drive is
having problems reading the original data. If all drives
have problems reading the pack, a problem should be
suspected in the original drive where the pack was
formatted.

•

If the compatibility problem appears only on customer
data packs be sure to have the customer back up his data
before alignments, or replacing hardware.

8.2

INCOMPATIBILITY SYMPTOMS

The following items are causes of incompatibility symp~oms:
1.
2.
3.
4.
S.
8.3

Head Alignment
Carriage Way Alignment
Dirty Head~
Write Current - E01, E02, A12
Bad Pack
ERROR SYMPTOMS

The following is a list of error symptoms encountered when
compatibility problems exist. Alsc. included are the most probable
failing unit and/or adjustment needed to correct the problem:
•

OCK errors are the most common error symptom of dr ive
incompatibility. It is usually common to a specific head
or heads.
If this symptom exists head alignment is most
probably needed on one of the drives. If alignment is OK
then a bad head or head matrix card E04 may be at fault.
Be sure to try to simulate the failure with more than one
pack as a pack could also exhibit this type of symptom.
HCRC errors indicate that the pack format may not be
compatible.
In this case, head alignment, a ,bad head or
matrix module E04 may be at fault again. When faced with
this type of problem, be sure to determine on which drive
the pack was originally formatted and if any head
alignments have been performed since that time. Constant
HCRC errors between drive may indicate a possible
miscalculation of the Header CRC word in one of the
drives and would be due to a failure of the M768S.

•

If the problem was isolated to a dr ive that is wr i ting
data that is incompatible with other drives the probable
failing circuits would be the Write Precompensation
(AI3), write current source (E01, E02, A13), or the
Matrix Module E04.

9.0

DATA BASE CORRUPTION

This section addresses problems that involve a ~loss of a
customer's data.
The common symptoms arei the system "hung",
"crashed", "deteriorated" and can't be brought up without
rebuilding the packs from a back-up tape or back-up disk packs.
This problem becomes very hard to isolate because the error
109gin9 file on the disk is usually highly intermittent.
8ecause
of the customer's sensitivity to this type of failure, the success
of isolating this type of failure hinges on a good acti.on plan
(isolation technique)
that is explained to the customer.
This
type of failures can be attributed to the disk subsystem and also
to such areas as the CPU, Unibus, memory, memory management, or
even software.
The following is a general isolation process that
one could use:
•

Determine the immediate history of whole system through
talking with the operators, users, customer, other
engineers, etc.
Check previous error logs for ,evidence
of any intermittent positioning problems such as HCE's,
or SKI that would indicate a dr ive going to the wrong
place on the pack.
When checking the error log, be sure
to note any system type errors (this would indicate a CPU
Unibus or Memory type problem).
Check field service
reports, site logs, etc. to get additional information.

•

Check for a history of MASSBUS Par i ty Errors ei ther in
error Register 1 or for a MASSBUS Data parity E~rror in
the RH Control Status I Register.
Parity detection has
one big fault - If you drop an even number of bits you do
not detect an error.
So it is possible to transfer data
to or from the· disk without knowledge of loosing or
destroying data.

•

If you suspect the system disk drive on a multi-drive
system, change unit numbers so that the system Disk
resides on a different drive.
In this case the error log
file may be available to analyze if you suspect: a disk
problem on the original system disk drive.

•

Note any changes in the environment such as installation
of new equipment (add ons, air conditioners, or other
office or industr ial equipment) that would affect the
power, loading, grounding, etc. on the system.
Power
fluctuation,
ground
failures,
improper phase/load
balancing have a high probabil i ty of causing these type
of problems.
Have an environmental specialist check the
site if necessary.
Be aware of any heat, humidity or
static conditions that may be excessive.

•

When you do get system time to run diagnostics, be sure
to start all the CPU, Floating Point (if applicable,) Mem
Mgmt, an~mory diagnostics before you start with disk
diagnostics (unless you have discovered in steps 1,2, and
3 that you definitely have a disk problem).
While running diagnostics check all the power supplies on
the system - especially the +Svol t regulators for the
CPU, Hem., RH and RM Adapter. Vibration testing may also
be helpful in isolating these problems.
(Please use
discretion as to the severity).

•

If you have a DECX11 system exerciser, be sure to vary
the default word count values in each I/O module for the
tapes and di sks on the system.
When running the
exerciser allow for at least one full pass of relocation
thru all available memory.

•

If you have isolated the failure to the disk subsystem
and not to a particular drive there may be a quick way to
isolate the RH controller by using another RH that may be
on the system. This usually only involves chang ing some
jumpers for the CSR, Vector Address, and number of
registers for the specific device. In the 11/70, be sure
to try the RH70 in another backplane slot.

•

If you isolate the problem to the RM05 drive itself and
have no error bit symptoms to go on, the drive is writing
indiscriminately on the pack and the problem is in the
write circuits.
This can be verified by taking the
corrupted pack and doing a spiral read header and data of
the pack.
Remember you must have previous knowledge of
any bad spots on the pack; any new bad sectors ind icate
there was a write error that was unrecoverable that
caused the data corruption.
For the 11/70, use the
Performance Exerciser diagnostic (CZRMU), Load and start
address 284, "R" Command with SWR :I: 3.
For VAX, use
Formatter (EVRAC) "Read All" command.
WRITE PROTECT THE
DRIVE!!!
NOTE
Above all, keep the customer informed on
what you are doing, why you are doing it
and
the
complexity of trying
to
troubleshoot this type of problem.

18.8

DRIVE NOT READY OR DRIVE HANGS

This section deals with problems where the only symptoms are that
the drive drops offline or appears to hang up (cannont be accessed
by the software).
This section should not be referenced when an
actual hardware error, such as DVC has caused the dr ive to go
"Offline".
There are
problems.

three

basic

symptoms

look

for

these

types

•

Loss of the VV Bit due to loss of MOL.

•

Loss Volume Valid (VV bit) without the loss of MOL.

See IVC.
See

IVC.
•

Dr ive does not return to a ready condi tion after a
command and does not have any spec if ic er ror symptom.
This symptom typically evidences itself intermittently
under the customer I s operating system and can bE~ caused
by numerous problems throughout the system.
In order to
isolate this type of failure, one must be on sl te when
the failure occurs, halt the sytem and examine the RM05
registers.
Pay particular notice to drive ready (bit 7
of the RMOS) not set and the status of the following
bits: VV, MOL, PIP, GO, OPR, ORO or PSEL.
The condition of these bits indicate the area of the
failure, i.e. the RM05 logic.
Specific failures will
depend on the conditions exemplified by these status
bits.
Also see RM02/03 Technical Tip on Fault Card
latching or errors.

11.0

DUAL PORT PROBLEMS

This section addresses typical problems with symptoms described as
-dual port access: -CR port hang/se1ect-.
All Port" arbitration
logic is located in the RM Adapter and provides the function of
deciding which MASSBUS accesses the drive at anyone time. Nearly
all dual port re1.ated problems can be isolated to the M7686
module, one of the M5922 or M5923 MASSBUS transceivers, or a
MASSBUS cable (Be06S or BC06R).
There are several things one
should know about the dual port option:
•

The dual port option is implemented by a jumper on the RM
Adapter backplane.
In addition to the jumper on the
backplane two M5923 modules, and the MASSBUS cables for
Port B are also required~
Dual Port

Single Port

backplane jumper 5 - 6 out, of Jl
•

jumper 5 - 6 in Jl

There may not be two drives with the same unit number
physically cabled on the same massbus even though they
may be stalected on alternate ports.

EXAMPLE:
ILLEGAL CONFIGURATION
MASSBUS A
(drive locked on A port)

Port
RM05
Drive 0

A Port
RM05
Drive 0
B Port

Locked
on B

locked
on A

B Port

MASSBUS B
•

The port select swi tch cannot be changed once the heads
are loaded, but will not effect the port selection until
MOL goes from low to high. This occurs when the pack is
spun down, and back up again.
The normal port select
switch change would occur whenever the pack is changed.

•

"Init" pulse does not clear the drive Attn bit if the
drive is selected on-the other port. _ (i .e. Unibus Init
doesn't clear ATA bit when the drive is select locked on
B port)..
Be careful when running DECXll as it uses
unibus "Init" to clear Attention bits. In order to clear
Attention bits on opposite ports, the attention summary
register (RMAS) must be written with a ·one" to the
corresponding Attention bit even though the drive is
locked on the other port.
EXAMPLE: If dual ported drive 1 is locked on the A port,
the B port Attention bit can only be cleared by writing a
000002 to the RMAS register on the B MASSBUS.

•

Customer written handler-for dual ported drives have been
known to have problems when dea 1 ing wi th the RPAS
register.
One reason is that the upper byte of the RPAS
register may be read as all "ones" or all "zeros"
depending on the condition of the Attn bits on the
oppos i te po r t.
Be sure tha t customer s use "byte"
instructions when addressing the RMAS register.

•

For 11/70 systems, the Performance Exerciser (CZRMU) is
ideal for worse case diagnostic testing. Run Performance
Exerciser from each CPU simultaneously.

12. "

PACK ERRORS

In the RM0S, as in all other third generation or higher disk
dr ives, the pack has become part of the electronics •. This is due
to the special information that is prerecorded at time of
manufacturing on the wservo surface w of the pack.
This
information is use.d both for posi tioning (in seekings & Track
following) and fc,)r timing to synchronize data being written and
read on the other Wdata surfaces w of the pack.
Because of the
complexity of these packs the RM05-P is the only pack we recommend
and furthermore, the RM0S error rate specifications apply to only
RM0S's with RM0S-·P packs.
We have no control over the packs of
other vendors that mayor may not function satisfactorily in
the
RM0S. We test each pack before we sell it.
•

No errors allowed on cylinder 0, track 0 and 1, because
this is the boot area.

•

No errors allowed on cylinder 822, track 18, because this
is the Bad Sector File area.

•

Not more than 20 uncorrectable sectors per" P" packs; no
uncorrectable· errors per "PX" packs; not more than 48
defective sectors per pack and not more than 10 errors
per surface. See 12.4.

•

If you have a pack that exceeds any of these conditions,
it should not be used for customer applications or as a
diagnosfrc meaia (XXDP).
It could however be used as a
scratch pack on which to run diagnostics.

•

Random DeH errors could be generated by a pack.
You may
also run into a pack that has one surface that gives
OCK's & ECHis. This usually looks like a head problem.

•

Intermittent HCE & SKI errors may be attributed to a pack
wi th excessive radial runout of the servo tracks (pack
wobble) or worn spindle bearings. This can be checked by
using the procedure in the Drive Hardware Maintenance
Manual under wTrack Following Check" - Page 2-80 of the
Installation & Check Out Section.

•

HCRC and DTE errors can be caused by bad spots on the
pack.
If these errors occur consistently on specific
addresses, this indicates the pack is at fault.
These
errors due to the pack should be classified as
unrecoverable (hard) errors and flagged in the bad block
map of the operating system. The Formatter program will
also flag them.

13.9

UNEXPECTED ATTENTION BITS

Attention bits are indicator (flag) bits to the RH (CPU
controller) that some important event has occurred in an RM05
(including the RM Adapter) on the MASSBUS.
This bit is used for
program interrupts to software (either operating systems or
diagnostics) •
Each· drive has a separate attention bit and· dual
po·rted drives have 2 attention bits; one for the A Port and one
for the B Port. The condi tion of the Attn bi t is sampled as bi t
Each drive's bit is also accessible in
15 of the RMDS register.
the RMAS register; the bit position in the register corresponds to
the drive unit number i.e., bit 9 of the RMAS register is the
Attention bit setting is usually caused by something happening in
Drive 9. It is rarely a problem by itself.
Please note the following hints:
•

If you intend to work on a dr ive off-l ine throw both
switches on the M5922 or M5923 modules, this will disable
all signals, including Attention bits, from the MASSBUS.
This would be advisable when using the RM05 Fi~a1d 'rest
Unit if the customer is running on other drives on the
system.

•

Be aware that MASSBUS parity is not used when accessing
the RMAS register on the MASSBUS.

•

Any "hung" Attn Bits (with no other indications such as
MCPE, MOPE or PAR) is usually traced to the M7686.

•

Many Diagnostic error printouts begin with "Unexpected
Attention" or "Attention from an Off-line Unit,." These
are rarely Attn bit problems and only indicate that one
of the conditions described in Table 13-1 has occured.

•

Attn in the RH sets SC (bit 14 of RMCSl) which sets Intr
which causes the trap (program interrupt).

The following is a Table of conditions that set the Attention bit;
take notice of the condition of port selection in order to see if
both A and/or B bits are set or cleared.

TABLE 13-1
CONDITION

ATTN/BIT

PORT SE;LECTED

1. Power up of RM~5.

set

Both A & B set regardless
of the Port selected.

2. Any error condition detected
in RMER1, RMER2.
(Attn will not set for errors
in the upper byte of RMCS2 or
the TRE and MCPE conditions).

set

Only the Attn bit of the
selected port.

3. Successful completion of a

set

Only the Attn
selected port.

bit

the

4. Successful completion of an
Offset or Return to
Centerline command.

set

Only the Attn
selected port.

bit

the

s. Any change MOL bit (the

set

Both A & B set regardless
of port selected.

6. In Dual Port Programmable
mode, a port request is made
and the drive is busy on the
other port, when the drive is
released the Attn bit sets on
the requesting port.

set

The requesting port's
bit set.

7. Unibus Init or drive clear
command.

clr.

Clear Attn bit only on
dr ives selected on the port
issuing the command or
Init.

8. Issuing any command with the
Go bit set.

clr.

Only the Attn bit of the
selected port.

9. Writing a 1 in the RMAS
position the respective drive

clr.

any corresponding Attn bit on
that particular bus
regardless of port
selection.

seek command.

online condition either the
drive going online, offline,
or into standby).

14.0

ADJUSTMENTS

If the drive adjustments; negative or positive 5 volt, Course
Position Gain Integrator Gain, and Fine Velocity Gain are found to
be grossly off, replace the associated module providing you know
no one has tampered with the adjustment-previous to your checking.
The reason for module replacement is that a component has degraded
drastically, and it would be better to replace the module now,
than to do an adjustment and have another failure shortly
afterwards.
14.1

SERVO ADJUSTMENTS

Extended Drive RM0S 11/70 diagnostic (CZRMV) and Functional RM05
VAX diagnostic (EVRDB) timing tests are a great tool for
troubleshooting velocity problems. Remember that a KWllP Clock is
necessary to do the timing tests on the 11/7e.
Two known symptoms that the timing test indicates are:
1.

Forward and Reverse Seek times differ more than 1 millisecond.

The Maximum Seek Time is too slow although the Average
Seek time is at the minimum.

Both these symptoms indicate a problem. Usually A20, Al9, or A07
can cause the problem, but the Servo Power Amp or the Veloc i ty
Transducer can also.
14.2

FINE VELOCITY GAIN

In some cases when the head load occurs osciallation will start.
If oscillation of the positions exists, Fine Velocity Gain is
adjusted too far off. Readjustment will correct the oscillations.
•

Scope test point C of of the A20 card.

•

Observe the see Hz sinewave.

•

Adj ust the pot until the sinewave dissappears.
You are
now within specifications range for timing adjustments.

If oscillation persists change the Tach Rod Magnet. This is done
because the Tack Rod Magnet is of low magnetism. This will cause
the field in the coil to collapse and the result will be that the
heads will have maximum velocity, and hit the crash stop.

14.3

HEAD ALIGNMENT

If head al ignment. is necessary and the offset is more than 200MV,
have the customer back up all his packs that were wi i t ten on the
misaligned drive before doing the alignment.

15.9

FLOW DIAGRAMS/TEST POINTS

The flow diagram contained in this section are to ~id you in
troubleshooting the following areas of the RM9s Disk Drive~
•
•
.•
•
•

Power Distribution (one flow)
RM9s First Seek (four flows)
RM0s Forward/Reverse Seek (four flows)
NRZ to MFM Write Data (two flows)
RM0s Unload/Power Off/Emergency Retract (two flows.)

These diagrams give the print set cross reference numbers so you
can correlate the flows to the print set.
The flow diagrams are
labeled as Figures 15-1 through 15-5.
In addition to the flow diagram' there are several tables which
give you the proper test points to scope. These tables are to be
used in conjunction with the flow diagrams. The tables will list
the following:
•
•
•

Print Set Cross Reference Number
Proper Test Point
Signal Names

These tables are labeled as Tables 15-1 through 15-8.
These
tables are for both the NON-VDE and VDE versions of the RM05
drives.

803

GENERATE
+2OV

803

822

ENABlE

2OIW220
VACPOWER
803

ENABlES

RELAY
COilS

...."IJ
,.,s:::

803

DEVELOPS
-16V FOR
+16VSENSE

APPlYAC
TO A101
TRIAC

....VI

.-I

803
-T1 ENABLE

TURN ON
BLOWER

DEVELOPS
16.46VAC

MOTOR
803

DEVELOPS
16VAC TO
BRAKING
BRIOGECR14
804

DEVElOPS
28.20.10
VAC
803
812

803

DEVELOPS
-13VFOR
EMERGENCY
RETRACTCKT
822

.:(D

,.,
0
....
til

+9.7 SENSE

+5V REGUlATOR
CAl CHASSIS) 844
SERVO PREAMP 762

,.,r1'
....C"

842
5V REGULATOR
tAl CHASSIS)
SERVO PREAMP 762

rt'
....

::s
lOGIC CHASSIS 842
IAl CHASSIS)
REAOIWRITE
IAJ CHASSIS)
CHASSIS 612

READtWRITE

IAl CHASSIS)
CHASSIS 612
803

DEVELOPS
:t46VOLTS

VOICE COl..
fA 1 POWER SUPPLY)
POWER AMP 832

822

RMOS POWER DISTRIBUTION

Cl-Ot ••

....ts.1

,.,c::
CD
~

..,

,.,....
CD
rt'
PICK OUT

til
CD
CD
~

t il

::r
CD
CD
rt'

CB3TRI"PEO

PACK

MOTOR
STARTS

104

tf:trlf
K3 K4 K5

, n

I ENABlE I I
lHZOSC

1104

0
H\

1104

.e.
IOC

READY
FLASHER
lEO
82

Cl·_

RMOS FIRST SEEK

...,

....
\Q

PICK OUT
. - - - - - . TO NeXT DRIVE

..,C
(D

\on

'"
~

St
U1

.,....

C'1'

-UNlOAD HEADS >---...."

fI)

CD
CD
i'\

f I)

:::T

CD
CD
C'1'

'"0
~
~

TURN ON
Q1. START

FWD MOTION

CARRIAGE
ACCELERATES
FWD AT7 IPS

FWOEOT
DETECTED

....
..,c:
en
....U1
t'I,1

192

N
YES

FAUlT TO
INTERFACE

S
U1

..,....
t'I,1

(I)

r1'
til

en
en

SETl.OAD

LAtCH

t il

::T

en
en

RESET

SlOPE
FIF

0
1"'1\

0131072

RMOS FIRST SEEK

t'Ij
I-h
A-

EOTOETECT

..,t:

YES
184

(I)
~

I
l\,)

S
U1
t'Ij

..,

I-h

........

WHBIRNE

til

ANALOG

ISOVOllS

(I)
(I)

193

til

::r
(I)
(I)

rt
.&110

0
t1\
.&110

DIRECTION

r-----------__

FIF
--~

CARRY BIT
TO

1 A LOGICAl 0 IS FWD A2-A12-138
A LOGICAl 1 IS REV'

....,

LOW

ORDER

w
ENABtE
SELECTED
CHANNEL
REOTAANS

ADDER

122 - 123

GATE

.,o
C
.,
Of

ON CYl • CYl SEL • SER ROY

(I)

<
(I)

m
(I)

(I)
(I)

::T
(I)
(I)

-START SEEK

DIRECTION BIT

IT N
COARSE
POSITION
ERROR
VOLTAGE
203

CONDITION
DIRECTION
F-F
72

CONDITION
SLOPE FIF
72
ENABLE END
OF TRAVEL
DIRECTION

EW ADDRESS

20
CONTROLLER .~_..._ _ _ _...
DROPS TAG 01

....

192

LI'

INmATE
30 S
ONE SHOT
73

SET
SEEK
LATCH

START SEEK

IN(11ATE

1.2p

DROPONCYL
AND SEEK END
FOR JO,LS
TO INTERFACE

OROPONCYl
AND SEEK END
TO INTERFACE
125

YL.__

203
DIGITAl TO
ANALOG
CONVERTER

POSITION
CONVERTER

~rCYl_.....J~

REV

203
DESIRED
VELOCITY
GENERATOR

DIFFERENCE
COUNTER
DECODED

203

125
VELOCITY INTEGRATOR
CLAMP

[)IAOUTPUT
FOR TRACKS
TOGO

-FWD

125

203
CZ-01M .

I'IJ

'-'l
C

..,
CD
....
U1

CURRENT

- COARSE

FEEDBACK

w
GENERATE
VELOCITY
FROM MOVING

I'IJ
0

..,
..,AI-=

CARRIAGE
202

0........

..,
CD

m
CD

§tj
I
I
CARRIAGE ..
MOTION
fWDI'REV

GENERATE

{J)

GENERATE
C\'l DET A
C\'lOETB

CD
CD

C\'lINOER PUlSE

70
{J)

::r
CD
CD
rt

TMCK SERVO I--L..I-......

SIGNAl

204
832

0
t'tt
FINE ANAlOG

-&..----14

cz_

-T?128---_

-41F>---"

DEVElOP
CYlNlER

INOlATE
10"S
ONE SHOT.

PUlSES

....
U1

T~ 1 - - - - - .

4A~-----------~
CYlPUl.S£
BL.ANK..G

FWD OFfSET

;

SET

DEVELOP
FINE
ENABLE

FINE
LATCH

193

REV

OFFSET
+OFFSET COMMAND
OR-FtNEeHOlD.

I-~r--"'"

1N"",T1: 1.75 MS
ON CYlINDER 1-----.........
D£L~

GENERATE
fI\IE POSITION
ANAlOG SIGNAl..

193

194

STOP CARRIAGE
ANDSERYO
ON TRACK

serSf:EK
ERROR LATCH
3
73

FINE POSIT1ON
ANAlOG CONTROl
SIGNAl TO
SERVO

t il

:::r

+ seRVO

CD
CD
rt

ONCYUNDER
TO INTERFACE

READY
13

SETON
CVLJNDER

.r:.

o
.....

fIF
LAST COUNT

TO DtFF
COUNTER

T=O
72
72

RESET
SEEK
LATCH

.r:.

PREVENT
CYliNDER
PULSES

a·ou,

AlLaN A WRITE

GO SElECT

CIt 1174

CH I 01X, 02)(

r - - -........
~ DfSIRED

• _ _ _ •• EO....

IHO

I\~.~

~f613

813..

·)YES

L- RECE:
AND
TRANSMITTERS

022, 024

l.lE..IfOCATE A
FAUlT CONDIT1ON
AND DISABlE
WRITER

DISABlED

FAULT

r--

WR11DATA

0--. CHANNELl
WRITE

WR1lClk

DATA
WRITE ClOCK

Z
::0

813

ENABlE WRITE
GATE SYNC F1F I - -

rt'
0

132

DECISION

,--~

WN)()W

.uDATA

JEll AIEO a.oac

1S3t.a

EO'

I------,-32------'
fIF

WRTa.K

133

ENABlE UN
DATA RECEIVER

f----

MIl
WIlT
MTA

622

ENABlE WRITE
TOGGl.E F1F

I---

DATA

BUFfER
132

SYNC PUlSE
WINDOW

132

::J"

INITIATE A 1.5 P
~ DELAY OF WRITE I - -

DECODE
SHIFT
REGISTER

132

FAUlT

813

CIl

622
L-.,.

(J)

rt'

I-~---------~
13

..,~
....
rt'

132

k{;

~-----~

.e.

DlSAStE RAW .
READ DATA TO

READPAEAMP

013

FROM aJInRDllER

172

....

-I

.....

NOT ON CYl

osc ..
0IMI'El1
WRITE DATA
WRlTEa.OCK

(J)

AlLaN A WRITE
OR READ AND

GATE
'---------'
022

AND BIT 0

..,C

112

~\YlS_;;~e-J~- -;<NE~_~"~ =
' /

.....
\Q

~ AND READ GATE
TOGETHER FAULT

(J)

rt'

.....
0
H\

trODECODE B

N
CZ..,17

SYNC PULSE
WINDOW

-ADDRESS
,'SGATE

DELAYUNE
IN NANOSEC

O'S GATE

133
12

XX1!)

DECODE
(-EARLY)

SHIFT
REG

.....
U'I

.c.

132
X011

DECODE

}---.....

(-LATE)

132

.....
~

RECEIVE MFM

TRANSMIT MFM

DATA TO
WRITE BOARD

r -...........- - - . . . -..

133

DATA FROM
DECODE
622

)(001

DISABlE WRITE

DECODE
(-EARLY)

OF WRITE GATE

FAULT AT TURN ON

132
1000

DECODE
(-EARLY)
132

t il

WRITE

TOGGLE
F/F

DRIVER

+WRITE PROTECT

::r

}sa.£CJm _......, ...

CD
CD
rt

OLC
622

+WRfTE VOl.TAGE SENSE

-WRITEIGATE

CAR. BIT 9 - - - - - - GKF
CAR. BITS
CURRENT
CAR. BIT 7
LEVEL SEL

WRrrE
SENSE
FIF

622

613

8RD

XlV StnFT

622

-WRrrE
CURRENT FAULT
Cl·O'"

~~
GJtSl

nUl
,...

c:
-::s

tIl~

::ro

(l)GJ

,...,
fDa.

RaAYS

-,ev
APPLIED
TO COlt.
fAOME.R.

812

CI4P tC91

K3
K4
K5

KS
K7
K8

SPEED
OAIYE MOTOR
BRAKE POWER
HEADS LOADED

EMERGENCY RETRACT
DRIVE MOTOR ISOLATION

.... d'
o~

~..,

tz3

afD

..,

\Q
fD

::l

~ r.~. . OfF_.JH. .
.... """

_1UM_O_l__

_MrJ#IDr_i'tiEi.A_-_'ff-oJ

•

112

81'

Table 15-1

Power Distribution Test Points NON-VDE:

Print Set Cross
Reference Number
893
822
792
822
822
822
822
822
822

Test Point

Signal Name

CB2A
AlTB2-5
A3PJ4-A
AlTBl-6
A1TB2-3
A1TB2-2
A1TB2-5
A1TB2-1
A1TB2-8/7

Circuit Breaker*
+29 V
Pack Cover Solenoid
-16 V
+9.7 V
-9.7 V
-29 V
+28 V
+46 V

* Warning! Line Voltage
Table 15-2 Power Distribution Test Points VDE
Print Set Cross
Reference Number
893
792
804
804
804
804
804
804
894
Table 15-3
Print Set Cross
Reference Number
803
803
893
772
792
812
804
804
802
792
174
173
082
812
082
074

Test Point

Signal Name

CB2
A3PJ4-A
CB6-5
CB7-6
CB8-7
CB8-8
CB3-1
CB5-3
.CB5-4

Circuit Breaker
Pack Cover Solenoid
+9.7v
-9.7v
+20v
-29v
+28v
+46v
-46v

First Seek Test Points NON-YDE
Test Point

Signal Name

A1TP6,7
A1TP5
A1TP4
J20l-12B
PA83-06B
P8-06
J7-2,3
J7-7
J4-F
PA83-03B
A17-TPD
A17-TPB
A08-2"7B
P5-22
A08-TPC
A07-23B

C.B.7, +20v
C.B.6, -9.7v
C.B.5, +9v
Start
(Start)
Pick
Motor*
Motor Speed Interlock
Pull Speed Relay
Speed Pulses
Speed Pulse Sense
Up to Speed
Pull Speed Relay
Pull Speed Relay
Up to Speed Delay
Up to Speed Delayed

Table 15--3
Print Set Cross
Reference Number

Pi rst Seek Test Points NON-YDE (Cont)
Test Point

Signal Name

2f2J4
2f2J2
063
074
074
072
f2J73

A20-32B
A20-26A
A06-16A
A07-24B
A07-06B
AB7-16A
AB7-1SB

072
064
063
074
2f2J4
f2J74
063
f2J64
063

AB7-04B
A06-06A
AB6-27A
AB7-31A
A20-27B
AB7-12B
AB6-3SB
AS6-2SB
AS6-S7B

074
063
194
f2J72
073
f2J72
073
f2J72
f2J74
072
174
174
f2J84
2f2J3

A07-29B
Af2J6-30B
A19-22A
A07-1SA
AS7-03B
Af2J7-17B
AB7-32A .
A07-Al.7
AB7-1SB/97B
AS7-04B
A17-12B
A17-26B
A0S-31B
A20-12A

Forward Current
Velocity Transducer
Forward EOT Enable
Heads Loaded
Load + RTZ
Fine
Load + RTZ + Seek
Error
Slope
Set
No Servo Track
Servo Fault
Heads Load
RTZ
Rev. EOT FF
Fine Enable
odd Dibits + Fwd EOT
Enable
Heads Load
Rev. EOT FF
Fine Position Analog
On Cylinder Sense
ON CYLINDER FF
T < 1
SEEK END
ON CYLINDER PULSE
SERVO READY
SLOPE
READY
UNIT READY
TRIGGER
TRIGGER

* WARNING! LINE VOLTAGE

Table 15-4
PRINT SET CROSS
REFERENCE NUMBER

Pirst Seek Test Points VDE

TEST POINT

SIGNAL NAME

894
894
S94
772
792
823
S9S
895
S92
792
174
173
"82
822
9S2
974
294
202
063
974
974
972
"73

AITP6,7
A1TPS
A1TP6
J291-12B
PAS3-96B
A1J4-4
AIJ7-2,3
AIJ6-7
A1J4-F
PA83-93B
A17-TPD
A17-TPB
A98-27B
J4-6
A9S-TPC
A97-23B
A29-32B
A29-26A
A96-16A
A97-24B
A97-96B
A97-l6A
A97-1SB

072
964
963
974
294
974
963
964
"63

A97-94B
A96-"6A
A96-27A .
A"7-31A
A29-27B
A"7-12B
A"6-3"B
A"6-2SB
A"6-"7B

974
963
194
972
973
972
973
972

A"7-29B
A"6-3"B
A19-22A
A"7-1SA
A"7-"3B
A"7-17B
A"7-32A
A"7-Al.7

CBS, +2"V
CB6, -9.7v
CB7, -9v
-Start
(Start)
Pick In
Motor*
Motor Speed Interblock
Pull Speed Relay
Speed Pulses
Speed Pulse Sense
Up to Speed
Pull Speed Re le' y
Pull Speed Rele'y
Up to Speed Delay
Up to Speed Delayed
Forward Current
Velocity Transducer
Forward EOT Enable
Heads Loaded
Load + RTZ
Fine
Load + RTZ + Seek
Error
Slope
Set
No Servo Track
Servo Fault
Heads Load
RTZ
Rev. EOT FF
Fine Enable
Odd Dibits + Fwd EOT
Enable
Heads Load
Rev. EOT FF
Fine Position Analog
On Cyl inder Sense
On Cylinder FF
T < 1
Seek End
On Cylinder Pulse

Table 15-4
PRINT SET CROSS
REFERENCE NUMBER
074
072
174
174
084
203

Pirst Seek Test Points VDE (Cont)

TEST POINT

SIGNAL NAME

A07-10B/07B
A07-04B
A17-12B
A17-26B
A08-31B
A20-12A

Servo Ready
Slope
Ready
Un it Ready
Trigger
Trigger

* Warningl Line Voltage
Table 15-5
Print Set Cross
Reference Number
022
122
122
072
065
073
072
073
125
072
122
073
073
073
125
072
073
072
203
203
203
204
184
184
072
194
072
064
072
194
194
204
202
063

Forward/Reverse Seek NON-VDE And VDE
Test Point

Signal Naae

A02-03B
A12-13B
A12-07A
A07-30B
A06-33A
A07-11A
A07-04B
A07-TPC
Al2-07B
A07-16A
A12-13B
A07-TPB
A07-e3A
A07-32A
A12-07B
A07-A4.B
A07-TPC
A07-16A
A20-A4.4
A20-TPB
A20-Cl.l
A20-2SA
A18-TPF
A18-TPG
A07-e4B
A19-22A
A07-13A
Ae6-21A
A07-17B
A19-Cl.1
A19-TPC
A20-TPC
A20-32A
Ae6-l6B

+Tie High
Rev + Fwd
On Cyl & Cyl Sel & Sr Rdy
Cylinder Pulse Blanking
Maximum Address Fault
Seek Error
Slope
Start Seek

T=0

Fine FF
Rev + Fwd
(Seek)
On Cylinder
Seek End
T=0

Direction
Start Seek
Fine FF
D/A Converter
Position Converter
(Velocity)
Summing Amp Output
Cylinder Pulse Detect A
Cylinder PUlse Detect B
Slope
Fine Position Analog
Velocity Integrator Clamp
Fine Enable
T < 1
Fine Position Signal
Fine Position Analog
Current Sense
On Cylinder Sense
Forward + Reverse EOT

Table 15-5
Print Set Cross
Reference Number
084
073
012
032
012
032
072
125
084
184
184
062
073
072
Table 15-6
Print Set Cross
Reference Number
012
022
032
042
612
024
022
172
172
613
132
622
622
613
013
013
104
053
053
132
132
132
132
133
133
133
622
612
fi22

Forward/Reverse Seek NON-VDE And VDE (Cont)
Test Point

Signal Nalle

A08-31B
A07-llA
A0l-07B
A03-07B
A0l-24B
A03-24B
A07-Al.7
A12-07B
A08-31B
A18-TPF
A18-TPG
A06-TPC
A07-30A
A07-07A

On Cyl inder Sense
Seek Error
Seek Error
Seek Error
On Cyl inder
On Cyl inder
On Cylinder PulsE~
T=0
Trigger*
Trigger*
Trigger*
Trigger*
Trigger·
Trigger·

Write Data Test Points NON-VDE and VDE
Test Point

Signal Name

A0l-21B
A02-03B
A03-21B
A04-03B
E01-TPF
A02-TPB
A02-27B
A17-22B
A17-23B
E0l-TPC
A13-TPD
E02-08B
E02-0SB
E0l-TPW
A0l-l0S
A0l-l0A
A10-30B
A05-l6B
A05-22A
Al3-A4.0
A13-TPE
A13-A2.6
A13-B2.3
A13-27A
A130268
Al3-29A/8
E02-B2.9
E0l-TPX
Ee2-TPX

Pull Up
Tie High
Ch II Enable
Ch I I Enable
Multiple Head Select Fault
Control Select
Write Gate
Write/Read Fault
On Cylinder (W+R) Fault
Read Enable
Write Gate
Write Enable
Write Enable
Write Fault Blanking On
Write Data
Write Clock
High Frequency Clock
Write Data
Write Clock
Wr i te Ga te Sync
MFM Data
Sync Pulse Window
lIs Gate + 0's Gate
Compensated MFM Data
Address Mark -Enable
MFM Data
Write Toggle FF
Current Control
Write Sense

Table 15-6

Write Data Test Points NON-VDE and VDE (Cont)

Print Set Cross
Reference Number
622
622
613
623
S62
Table 15-7

772
SS2
812
8"'3
082
074
S74
S74
072
S72
204
204
082
812
812
813
813

ES2-C2.5
E02-TPC
E01J2-S7A
TPE
A06-TPC

Write Sense FF
BRD
Write Gate
Write Fault
Trigger·

Test Point

Signal Nalle

J201-12B
A08-27B
AP1S-22
A1PS-l9
A08-24A
A07-29B
A07-12B
A07-06B
A07-16A
A07-16B
A20-B1.1
A20-B1.l
A08-27A
A1PS-02
A1PS-04
YFN
A1PS-01

Start
Pull Speed Relay
Pull Speed Relay
K7 Power
Unload Heads
Load Latch
RTZ Latch
(Load.RTZ)
Fine
Coarse
(Load.RTZ.Fine) Gate
(Load.RTZ.Fine) Gate
Pull Motor Relay
PUll Motor Relay
Tr iac Power
Brake Latch
PUll K8

Unload/Power Offl Emergency Retract Test Points
VDE

Print Set Cross
Reference Number
772
S82
822
8S4
S82
S74
(')74
S74
(')72
S72
SS2
822

Signal Nalle

Unload/power Off/Emergency Retract Test Points
NON-VDE

Pr int Set Cros;s
Reference Number

Table 15-8

Test Point

Signal Name

J201-128
A08-27B
J4-S6
Jl-lS
A(,)8-24A
AS7-29B
AS7-l2B
AS7-S6B
AS7-l6A
AS7-l6B
A08-27A
J4-9

Start
Pull Speed Relay
Pull Speed Relay
-46 Emg Ret Vol t
Unload Heads
Load Latch
RTZ Latch
(Load + RTZ)
Fine
Coarse
Pull Motor Relay
Pull Motor Relay

NOTES

RMOS SERVICE ADJUSTMENTS AND PROCEDURES

LOG I C tHASS 15
(tARO SID£)

UlTUUTOR

lAIN ADJUst

+S Volt and -S Volt Adju·s·tments
1.)
2.)
3.)
4.)
5.)

Useinq the FTU or hand toggle, command continuous
seeks between cylinders 000 and 128.
Connect positive voltmeter lead to A2JD94-04A
on logic backplane. Connect negative lead to GND
on the regulator card.
Adjus,t +5 (ltl') to measure +5.1 Volts (+0.05 V).
Connerct negative voltmeter lead to A2JDJ4-01A
on lOrgic backplane. Connect positive lead to GND
on the regulator card.
Adjust -5 (lt3) to measure -5.1 Volts (:to.OS V).

Head Alignment 'Procedure
1.)

2.)

Install head alignment card in logic rack A2.
Connect FTU and meter leads.
Mount CE pack on drive and allow it to thermally
stabilize. CDC recommends that the pack be spinning
with heads loaded for at least 60 minutes.

If the CE pack has just been removed from
another drive which had been running for 60
minutes and the drive you are installing it
on has been running for 60 minutes, then the
recommended stabilization period is 15 minuteso
3. ) Read the RHOS head alignment flow chart. Pel;'form
The servo head offset check.
3A. ) Set the alignment card Servo/Read-Write switch to
the Servo position. Set X.l/Xl to the Xl position.
3B. ) Command continuous seeks between cylinders 360,
and 365,for 30 seconds. Command a direct seek 'to
cylinder 004.,
3C. ) Compare dibit pattern with example in this book.
Toggle the Positive/Negative switch and record
readings in both positions. Meter readings to the
right of zero are positive and readings to the
left of zero are negative. The positive value minus
the negative value equals the amount off Offset.
Or ••• (P) - (N) - OFFSET.
3D. ) If the amount of offset is outside the +60 mV
range, there exists a problem in the servo system.
3E. ) Next, ,command a direct seek to cylinder 005.&
Repeat steps 3C and 3D. ~dd offset readings from
cylinders 004eand 005., This sum should range
between +75 mV and -75 mV. If it doesn't, you
have a problem in the servo system.
A

•

I '

:...::....~..I.~...:~...::...::...::...::...::...:
J

j
(~

I CHI

.. L.l
................
t ......
...
.. ..1..............
...
\\
~

OSCILLOSCOPE
SETTINGS
CHl- 2 volts/dive
CH2- Not Used
Time Base
A- 2uS /div.
B- Not Used

CH2

Triggering
INTERNAL POSITIVE

CHl- Connected to
Dibits Test point
Y
on alignment
BALANCED DIBIT PATTERN
card.
4.) Command a direct seek to cylinder 7538 Install
carriage locking pin into alignment hole.
5.) Set S/RW switch to the RW position. Calculate the
offset of all read-write heads by the same me't.hod
used in step 3C. If all offsets fall within the
+150 mV range then the alignment is within splec.
6.) Xny head that is greater than the +150 mV ,range
is mia-aligned. If any head is +30~mV offset, then
back;up the data pack for this arive before continuing
to the head alignment. Remove alignment pin from
drive.
88

.uAftO
Olsee

,.. ~

•

:
:
:

ill

I-

• '-

• ,..

.. --

::
::

•

1....0

L-

tUAftO
DISK

RMOS Head Arm
Alignment
RHOS Head Alignment
Flow Chart
.." ..

:~~~ ALJ'NMENT

M£AD AItM
ALIGNMENT
SLOT

DISTANC£S
APPROX.
EQUAL

&.
CAUTION

ALI'NMZNT TOOLS ON SOME DRIYES
CANNOT IE ROTATED MORE TMAN 1S0~
10tATlNG TOOL IUOND IIcr MAY
DAMAGE MEAD SLOt OR ALIIIMENT TOOL.
It:AD-AaM

A ..

- -......
-.,-A 0

AU'NME.T~"/
TOOL
•
t:?"

&
'It

0
0

&"
'15·

AIRIAI£
IEAD... RM
CLAM' I.'
SCltw

,U17-1

***********************CAUTIONS*************************
These two notes appear in the CDC Service Manual
for the RHOS and are well worth memorizing before you
attempt a head alignment.
If the heads perform an unscheduled retrllct and the
START and FAULT lights are both off, immediately turn c)ff
the +20Y breaker. You have dropped +5 Volts and run thE~
risk of burning up the voice coil. Only after you've thus
diabled the DC power supply should you check to see if
the power-down resulted from a failure on the AC line. The
blower will still be on if the AC power is OK.
Caution '2: Should an emergency retract occur with
the locking pin in the alignment track lock hole, the
following may occur.
1.) Blown fuse
2.) Tripped DC circuit breaker
3.) Blown power amplifier transistors
4.) Any of the above = Unretracted heads on a
statioJ\ary CE pack.
Head Alignment Continued •••
7.) If heads 16, 17, or 18 require adjustment,
move the servo preamp cover before proceeding.
(At this point the drive should be stopped.)
8.) Loosen screws on the heads to be adjusted and
torque them to 4 + 1/2 lbf-in.
9.) Start the drive and command a direct seek to
cylinder 753-e
NOTE
Force exerted during head alignment can move the
heads from the alignment cylinder to an adjacent
cylinder, resulting in an improper alignment.
Prevent this by connecting a jumper from A07-llA
(seek error) to ground. Be sure to remove the
jumper before commanding another seek.
If you use this jumper, remember to put the jumper
on the signal end while the power is off. Then, when
the drive i, powered up and on cylinder, place the
other end of the jumper to ground.
10.) Using the FTU, select the head to be aligned.
To prevent personal injury, place the locking
pin in the alignment track lock hole. Remember
to remove it before commanding another seek.
11.) Install head alignment tool so that the tool
pin engages the hole in the head-arm alignment
slot. Observe the oscilloscope and adjust hE!ad
to obtain a balanced dibit pattern.
12.) Observe the null meter and adjust the head until
the offset is less than + 7S mV. If head cannot
be brought into alignment, you may have to l:ecenter the servo head. Any adjustment of thE~
servo head will require realignment of all data
heads.
90

13. ) Remc)ve carriage locking pin and also the
jumper from A07-11A. Spin down the drive.
14. ) Final torque all the heads to 12 +1/2 1bf-in.
15. ) Spin up drive and check to see that all heads
adjusted are within specifications. Readjust
those which are outside of the + 150 mV limits.

When head alignment is complete, perform all servo checks.
SERVO SYSTEM CHECKS AND ADJUSTMENTS
The servo system adjustments are interactive and must
be performed in sequence to be valid. The servo system
flow chart shc)ws the order in which they must be performed.

'ERFORM
COARSE POSITION
GA~ ADJUSTMENT

faftOCEDURE

'ERFORM
INTEGRATOR
GAIN ADJUSTMENT
faftOCEDURE

SERVO
ADJUSTMENT
'''OCEDURES
COMPLETE

'EI"ORM
'INE VELOCITY
GAIN ADJUSTMENT
PROCEDURE

RECHECK COARSE
IIOSIT ION GA I N
ADJUSTMENT

VES

1.)
2. )
3.)
4.)
5.)

1.)

2.)
3.)

COARSE POSITION GAIN. Prepare the drive for use
wi t.h the FTU.
Command continuous seeks between 000, and 1466.8
Connect oscilloscope CHl to A07-03A (+On Cylinder).
Ext~ernal Trigger scope to A07-07A (-Forward Seek).
Observe display. If distance between on cylinder
pulses is not between SO to 54 mS, adjust top
pot:entiometer on card A20 to meet this spec.
INTEGRATOR GAIN ADJUSTMENT. Command continuous
seeks between cylinders OOO,and 200 .. Set up scope
as indicated in drawing on the next page. Adjust
the scope until the two sloped curves are displayed
as in the drawing.
You want to examine closely the second to last
di:scontinuity. This will require some fiddling with
the scope in order to lock this portion of the wave.
Adjust the bottom pot on the A20 board until the
wave is correct.
91

QIC.LbOlC(ft; lETTING!
LOIIC IHD TO ICOfII • •
*-Tl/DIV
Of 1- O.n/CM
Of I - MOT USED

""'DlY
A- O.

FWD

r-'--r-'r-~~~~F=4-~~EEK

MOTE:

SMSICM
1- MOT USED

HORtZ DISPLAY
SET TO MAG • 10

,........

:::g'l~l:~ EIT ON A12-17' (+T ~ 7)
MOK CONNECTIONS
eM I TO A20-TPD (+

CHI - NOT USED

OESnED VELOCITY)
IB:OND TO LAST DISCONT'N.lTY

MOTE:
IT IS NECESSARY TO INCREASE
VERTICAL SENSITIVITY TO MAKE
THIS MEASUREMENT.

NOTE: IGNORE THE SPIKES.

CJOMV

OK
'W18

INTEGRATOR GAIN WAVEFORM
1. )
2. )
3. )

4. )
5. )

FINE VELOCITY GAIN. Command a read in conjunction ~~ith
a continuous seek between cylinders OOOaand 001.8
Connect and adjust scope as indicated by the drawing on
the next page.
The top wave form in the drawing is an overshoot condition
which is not desirable. Adjust the middle pot on the
A20 module to as nearly as possible resemble the ideal
waveform. Best operation is attained with it adjusted
slightly toward the under shoot waveform which can be
seen in the final waveform.
Command a sequential seek between cylinders OOOsto
l466,in conjunction with a read.
Note that the displayed waveform should look similar to
the Final Check wavefor.m. If any overshoot exists
greater than 0.5 Volts, adjust the middle pot on ~ard
A20 until the specification is met.

pH.lbOSC9PE IETTlNGI

. ........ ..-.

.. .

'"....

~-I ~.. ... ... ...

LOIIt 11(0 10 ICOPI . . .

WLTl/OIy
CM 1- O. 5V/C"
CM 1- lOT uno

...

.11 \

"'~

,.../DlY
A- I"S/CM
1·'IOT USED

,........

...

I-

•

1-" •

-\ ~.. ... .•.. .... ... ..-. ....
10

•

I-

•

IDEAL

... IEGATIYE ON A01.3~nat
( -SEEk)
I-lOT USED

MOK CXNCCTIONS
CM. TO AU.T'C
(:+FIIIE POSITION ANALOG)
Of I - lOT USED

~~4::~~QIa~~';~-

INITIAL FINE VELOCITY GAIN
SlClu..MC9PE IETTINGS
LOGIC ONO 10 SCOK 'NO
CM"TS/OAY

Otl- O.SY/CM
04 2 - lOT USEO
TME/DlY
A- 0.1"51 CM

1_ lOT USED

fliGIIPING

A- ElT, A07.S0A (.SEEk)
I· lOT USED

. . . . CONNECTIONS

eM' TO AlI-TPC (+F1lt 'OS1110N ANALOG)
012 - lOT USED

100

~: fo····
100

•

1--•• -

•

.. .

1"' • • • • 1- ••••

U. .\

...-.

•

-- ~

Ie· ••• t- ••• - Ie· ••• 1" •• ' • t--•••
~

. ... . .

..-.. ...... ._... .....

100

-.. . -.. ....
~

...... 1----- Ie···· .. --- .... -

-t-

.... -"" -.. ..

FINAL FINE VELOCITY GAIN
93

RMOS Write Circuits Tests

WRITE COMPENSATED MFM
DATA WHICH PROVIDES INPUT
TO WRT DRIVE' CIRCUITS.

'.67 MHZ EIAILE SI'IALS WHICH
PROVIDE IASIC TIMI.'.

STEP 4

f£Sf£D '~Sfff ,
All-_
1IIU...wIIIgg,-.......-oiI. . . . . .I

TO .., ..

CONvE .. TE ..

LINE

NSATION

ItCY"

AND WItT

• .. ITE
O"IVE
CI"CUITS

102

CIRCUITS
All

...........-.TO Hf.ADS

102

i·"

101-T"-

laz DATA RECEIVED
nOM CONTROLLER.

FEEDIACK SIGNAL 'ROM OUTPUT
OF WRT DRIVER WHICH ,ROVIDES
CHEtK OF WRT DRIVE. AND HEADS.

TESTED IY: STE' J

TESTED 'Y: STE' i

1.)
2.)

Connect the drive to the FTU and command a 1010 bit pattern
write to the disk.
Check each test point from the block diagram above against
the waveforms on the next few pages. Scope set-ups are
included with each drawing.
QSCIu..OICQP£ • r i!!!lS
L.OIIC _

'n)1CGPI'"

\U.TS/fJAY
Ot I-O.IV/CM
CIt 1-0. ZV/tM

""'.V2MS/CM
A-

I-O.OIS/CM

m. . .

A- +ElT. AO.-T'C

1- -liT

(1IDEl)

..... CONNECTIONS (10l 'ROlES)
eM I 10 AU-T'I (IU DATA)
Otlta

AU·T,. (WIT STROlE)

•

NOTE: SET TO DISPLAY MODE TO ALT AID T'I"ER MODE TO CM 1 ONLY,
ALSO SET HoalZONTAL DISPLAY TO • (DELAYED SWEEP)
.....- -........-IDSttIU.

CHI

AlClu.p!ICOP£ IETTINGS
LOIIC .., 10 ICOfIIIND
-''''/DlY

CH 1- O. IY/C"
CHI- O. 2V Ie"

1WE IDlY

A-2"S/C"
8·0.05f'S/C"
~

A- +UT. A06·TPC (+INDEX)

I .. ·INl

. . . CONNECTIONS (lOX PROBES)
CH 1 TO A13·TP£ (Nn DATA)
Ot 110 E02-TPU

.OTE: SET DISPLAY MODE TO ALl AND TRIGGER MODE TO eH 1 ONLY.
ALSO SET MOklZONTAL DISPLAY TO B (DELAYED SWEEP)

CHI

RHOS Wri~e Driver Input
. OSCILLOSCOPE IETTINGS
LOGIC IND TO ~ tNO
WLTS/OAY

Ott-0.2Y/eM

CHI-O.2Y/CM
TIllE IDlY

A- 2MS.CM

1- O. os,..S I CM
~

A- .UT. A06·TPC (+IND£I)

1- -INT

"'*eM 1CONNECTIONS
(10l PR08ES)
TO A13-TP£ (NRZ 6ATA)
CHIlO £02·TPT

NOT£: SET DISPLAY MODE TO ALT AND TRIGGER MODE TO CH 1 ONLY.
ALSO SET HORIZONTAL DISPLAY TO • (DELAYED SWEEP)

CH I

CHI

RHOS Write Driver OUtput
9S

RHOS Read Circuits Tests
10 ItF'ltNtE tLK SIGNALS
'ROVIDE INPUT DUlING PLO
SnCHRON lZATI ON AND AM AREAS.

TESTED" :

HEAD

DIGITAL NRZ DATA SIGNALS
SENT TO CONT~O~~ER.

A"'LI::::~;~ 5~~= _T.UTED. ~\I:lP I
sm

...,.......-___

....0 AND
}
DATA
S"ARATOR ...._.......

A'S

AI.-OII

ANALOG DATA SIGNALS DtRIVED
,ROM SIGNALS DETECTED IY
ID/WRT HEADS.
TESTED IY: STEP 3

1.)
2.)

TO
C~NTROLLER

'IS-2••

DIGITAL MFM DATA DERIYED
'ROM ANALOG DATA SIGNALS.

10 Clit SIGNAL S

TEST£D 'Y: STEP 4

TtSTED tY: STEP 6

SENT TO CONTROLLER.

Connect drive to FTU. Command a write data, pattern 1010.
Command drive to read pattern 1010. Verify that all
waveforms are consistent with those shown on next few pages.
Scope setups are included with the waveforms.

RMOS Analog Read Data Waveform
LOGe GNO TO ICO'£ .NO
\1OLTS/OIY
CIt I - 0 • 1¥ I tM
CIt Z - O. 1¥ I eM

TIME/DIY

,- 2MS/CM
1-0.05 SICM

..........

,- +£IT. A06-TPC (+UDU)
1- -INT

PRCIE CONHICT~ (lOX PROIES)
CH' TO AU.081 (-ANALOG DATA)
CIt Z 10 A14-071 (+ANALOG DATA)
NOTE: SET DISPLAY MODE TO ADD AND INVERT ONE CHANNEL.
ALSO ~ET HORIZONTAL DISPLAY TO • (DtLAYED SWEEP)

'-....Z8IC) CIlC II . . /

QlCIWICXft ImlNGS
LDIIC . . 10 ICQIII£ ItOD
-.lI/OAV
0 .. - O.lY/CM

OII-O.lV/tM

""/01'1
A-IIIS/tM

e- 0.05S/tM

,.11EMiG

A- +UT.

e--IIIT

A06-TPC (+IIDU)

.... CONNECTIONS (,lOl 'IOIES)
eM 110 AI4·038 (+10 DATA)
01110 A14-041 (.10 DATA)
10TE: SET DISPLAY MOD£ TO ADO AND INVEIT ON CHANNEL.
ALSO SET "DRIZO"TAL DISPLAY TO • (DELAYED SWEEP)

-._-.-......
",

.",

_. ...
...
..
-'
"
..... ...-.. --_.- -.... .....-'"....';E-

_10-

I. • • • •

1--_ ••

:,
,

aU.
1- ••••
I-

J
...... 1-- •••

-'"

.",

1- ••• • 1- • • • •

-r-

..... 1----- ...-- ...-- ..._-.
-- --

-!~

-i-

-r-

RHOS Data Latch Output Waveform
READ CLOCK CHECKS •••
Use s~e setup as above except move CHl probe to AlS-24B.
Move CH2 probe to AlS-23B. Observe that the displayed
signal has a frequency of 4.84 Mhz.
10TE; SET DISPLAY MOOt TO ALT AND TRIaGER MODE TO tH 1 ONLY.
ALSO SET "ORIZONTAL DISPLAY TO • (DELAYED SWEEP)

_IU.OSCQP£ IETTINGS
U)IIC MD 10 . . . lNO

-.TS/DAv
Of' - O.U/eM

....- -......t-m:S(:tIO)N$

0I1-0.2Y1eM

hIE/DiV
A-IMS/eM

CH I

e-O.os"S/CM

.... CONNE~ (lOl 'R08ES)

CHZ

CM t 10 A15·27.
OtI1O A15-Z'.

.................... (1 ....

RMOS Read Data to Read Clock Timing
97

RM05 Head Amplitude Check
This procedure will verify that the amplitude of the signal off
of the R/W head is sufficient to allow reliable processin~r of data.
Amplitude i_s inversely proportional to the frequency of
recording data. Therefore, the highest amplitude will be
observed when reading all ones. The lowest amplitude will
be observed when reading alternating ones and zeros.
1.)
2.)

3.)
4.)
5.)

Connect drive t'o FTU. Command drive to seek to cylinder
l466.aCommand drive to write all ones on each head ojE that
cylinder.
Connect External trigger (negative) to A06-TPC (Index).
Connect CHl to E03-TPB. Connect CH2 to E03-TPC and set
display mode to ADD and invert one channel. Set Volt/div
and Time/divas required.
Command drive to read all ones and step through each head
in turn. The minimum level should be 130 mV peak to peak.
Command drive to seek to cylinder OOl,and write a 1010
pattern on all heads.
Command drive to read. Step through each head in turn and
verify that the amplitude of each is a maximum of 1100 mV.

Index Timing Check.
1.)
2.)
3.)

Connect CH1 to A06-TPC (+Index). Trigger internal positive.
Observe that the Index is a logic one for 2.5 (+0.3) uSee.
Observe that the time between pulses is approximately 16.7 mS.

Speed Sensor Output Check
1.)
2.)

Connect CHI to A17-l7A. Trigger internal positive.
Observe amplitude on scope. Signal should have positive
and negative amplit~des of at least 600mV. If not, t.he
speed sensor gap may be misadjusted.
SERVO AMPLITUDE CHECK
NOTE: SET DISPLAY MODE TO ADD AND INVERT ONE CHANNEL

QSCIU.OSCOPE SETTINGS
u:MIIC INO 10 scoPE 'NO

~
~.-

-I-

oi!-

...

.....•-1-._-....... -_ ......-.• __

.3 TO

'.1.1--•••••••••••••

-I-

Llv,..

...

I CHI

••

-I-

CHI- D.SV/CM

TlME/elY
A- 1,,5 eM

I · NOT USED

L .....1.. _...................................
~

_TS/DlY
CHI- O.SV/CM

"'....

A·INTERNAL NtGA'rIVE
I·NOT USED

eM2

. . . CCNCCTtONS
CH t TO A18.1S1 (-DII ITS)

CHIlO A18·238 (+DIIlTS)

AlCIUrQIC2E BY' " "
UIIIIC IND 10 IICON: . .

",./DIYo. n/CM (lEAD SCALE AS lOaMY)
.OT USED
,.'DlV'MS/CM

...
.....-'".... .... .... ...

Ott at 1A-

./
.,,-

Ie .OT USED

11I1101NG ('OStTIYE/EXTERMAL)

AI\

. ..... . ..... .....·
"'"

fo .. • .. •

i-••••

"" \

".,

I· IIOT USED

, . . . CClNCCTIONS
eM' TO AU·TPIC (nilE 'OS AIIALOG)

f'\ L
tEN 'tEl
.... ~.~ .- .,. .... ~...J..;..........
,,'"
·
1-••••

A- IIiDU

CH 1 -

,1-

"'"

1--' •••

"l-

~ INDEX S'INC

.OT uno

. .

'"..-. .... .-.. .... ... ... ..... .... 1-" •• ..... .......·

MOTES:
1. MORE THAN MORMAL RUNOUT RESULTS
IN THE WAVEFORM HAVlNG A 60 Hz
SlNUSOIDAL CII)MPON£NT AS SHOWN ON
•
WAVEFORM A. AS AMOUNT OF RUNOUT
INCREASES. TME PEAk TO PEAK AMPLITUDE
OF THE 60 Hz COMPONENT INCREASES.
2. NORMAL RUNOUT IS SHOWN ON WAVEFORM I.
IN THIS CASE. THE AMPLITUDE Of THE 60HZ
SINUSOIDAL COMPONENT IS ~ESS THAN
'OOMY PEAK TO PEAk.

-i-

.\.

.1-

'1-

- .- \ ... " j r. '"" "'"'

!l\} i\ J

..... ....• NOTE Z .. , fo···· ... ... ..... .....
. . . . .. .
.. "
I-!

. . :+....
~

RHOS TRACK FOLLOWING CHECK
Inability to stay on track may be aue to excessive pack or
spindle assembly runout. It may also be due to arifting or
'hunting' servo circuits or bad AGC action. Inability of the
heads to follow the track may cause read errors or occasionally
cause the drive to lose On Cylinder.
1. )
2. )
3.)

4.)

5. )

Connect the drive to the FTU. Connect the scope as
indicated above. (Index is A06-TPC).
Command a airect seek to cylinaer 620.,Observe the aisplay
using the above for reference. If the 60 Hz component is
greater than 400 mV, then excessive runout exists.
If runout exists, note the phase relationship of the 60 Hz
component.
Stop the drive. Note the position of the pack on the spindle
ana remove the pack. Replace the pack 90 degrees (1/4 turn)
from where it was. Start the drive ana command a direct seek
to cylinaer 620.8· .
Compare phase relationships with the signal now displayed
and the one obtained earlier.
a.
If 1;~he phase relationship of both waveforms are the
same, therl runout is due to the disk pack or a servo fault.
b.
If phase relationship has changed, then the runout is
due to the spinale or again a servo fault.

RHOS SERVO CHECKS
osc'LL05COP£ SETTINGS
LOGIC INO 10 ICON tNO

WLTS/DIV
Of 1- n/tM

at z- .OT USED

T./DlV

...

A- SMSICM
1- NOT USED
"..
A- NEG tXT. A07-01A (-FWD SEEK)
1- .OT USED
, . . . CONNECTIONS
CM I TO A20·TPB
CM

z .. NOT USED

D to A Output Check
The D to A converter produces some maximum value and steps down
as each track is crossed. It should produce 0 V when on cylinder.
The above waveform was taken doing continuous seeks between
cylinders OOO.and 200.,
Cylinder Pulse Blanking Delay Check
Command continuous seeks between cylinders OO~and 003.8 Connect
CHl to A07-30B (+ Cylinder Pulse Blanking). Trigger positive
internal. Observe that the Cylinder Pulse Blanking delay is a
one for 950 (~50) uSec.
Cylinder Pulse One Shot Check
Make same preparations as Cylinder pulse blanking check except
connect CHl to A07-22A (+Cylinder Pulses). Observe that t~he
cylinder pulse is a one for 10 (.2.5) uSec.
__
OSCILJ.OSCOPE RTTINGS

Cylinder Pulse Switching ~!vel Check
1I0Tl:

LOIC IND 10 ICOPI tNO

TIME/DIV AND PR08£ CONNECTIONS ARE
COMMON TO ALL THE FOLLOWING

jAJ.UOR!!L-- __
T./DlV

......I: ........ . \

A- .2 MSICM
I-NOT USED

1-- ••

PROlE CONNECTIONS
eM I TO A1a-09 a (+TRACIt SUVO S
011 - NOT USED
+O.4(t.l)V

....

I-

A-IIEG EXT. All-oal (+CYL DET I)
1- lOT USED

....

VOLn/DlV
CH 1- .lV/tM

eM 1- lOT USED

,. A- 'OS EIT. AlI·OI. (+CYLoCt..l)v
DET I)
1- lOT USED

GH'

.fo···· ... .... ... .... .... ...

1-••••

. .niDI"
CH 1- .5V/tM
eM 1- NOT USED

. .
.
.... .

100

'1-

.....
.~

1- ••••

ICHI

cylinder Pulse Switching Level Check
wavefor.m on the preceding page was taken under the following
conditions:
Drive connected to FTU. Command sequential seeks between
cylinders OOOeand 1466, (forward). The other two waveforms are
below this text.
~he

OICtU.OICO!J IITDNIS

.
.
...... ..... .... ...... ... ... ..... .... ....."....
~

_Tl/OAY

CH 1-. SY/tM
CHI-NOT USED

CHI

.-.

A- NEG EXT. Ala·on (+CYL DET A)
1- NOT USED

.~
.. .

/ ' K· .... ... ... V.... ...... ...........

CHI

•

OCt.OY
_Tl/OAY

CHI-.lY/CM
CH 2 - NOT USED
~

A-POS EXT. A1B-071 (+tYl DET A)
I-NOT USED

Fine Enable Switching Level
Connect the drive to FTU and command continuous seeks between
cylinders OO~and OOl.aCompare display with drawing below.

10TE: SET DISPLAY MODE TO CHOP.

OICtY.OICQ!I[ KTTtNGS
I

lAIC IND TO ICOfIE IND
_Tl/OAY

CH I ·SV/CM
CHI·O.SY/CM

TIIIE'DV

A- O. IMS/CM

.......

I-lOT USED

A-tIT 1£8. AZO-IZA (-fWD SEEl)

•• lOT USEO

....: CONtCCTIDNI
CM'TO A20·10A (~f'JlE liABLE)
CIt I TO A20.T'& (+IITE&UTED VEL)

101

NOTES

102

&J a CC>Nl"R.OL DATA
~ r::.I CORfO~TION

DIV.

AELD CHANGE ORDER

DATE APPROVED APR n A ~~n
,CO PACkAGE PI.

~I~ TE!Y UNIT

TB3A~A

'IELD UtIITI ."ECTU
TB1A~A

-.-OIIPCIM--iI'...
-- - - - - -.... SERIES CODE Dia THROUGH· It,

1-. -...

aMI ______
2 -..1___

6'05371:.6

a.",

.54280
PAGE I OF II
I
CLASS
l[

18
0

AffECTED BY FCO
'>
YES
NO 1 - - - - - - - - - - 1
~~~~~----+-~~D--t ••"==,~~_I_r
PUa..ICATIONS
~
_ _•

SEE lTEn It

SOfT_ _ CHECKOUT

0.11

SAfETY

• ALL HEAlS ON THE '71.1..
1. REASON fOR CHANGE: ALLOW TB3A~A TO SELECT

,r'I

'.C.O . • 0.

2. "'NUALS AffECTED: TB3A2A HARDWARE nAINTENANCE nANUAL (a33~~71D)
3. PESC!IPTION Of CHANGE: REWORK W/W ASSE"BLY AND ADD A 1101[ TO ConpONENT SIDE Of
LOG-IC BOARI.
It.

REfERENCES:

THIS CHANGE WILL BE INSTALLEI BY nANUfACTURING IN UNITS WITH SERIAL NUnBERS
3"0,3"a ANI ABOVE.

'I
s.
I .11

-if.I

IiE~

n~;
J~II
IIIE

iff'
11
.1
E'II.
I-·~

INSTALLATION PROCEDURE:

INOTE:I A 30 AWG WIRE WRAP TOOL ANI 30 AWG WIRE WRAP WIRE ARE·

REQUIRED fOR THIS CHANGE.

A. OPEN fTU TO GAIN ACCESS TO W/W BACKPANEL.
8."AKE fOLLOWING CHANGES TO WIRE WRAP ASSEnBLY:
PELETE:

ORIGIN
D~I:.-OJ.2

E30-DOb
[30-001:.
I

DESTINATION

LEVEL

JC3]'-03S

[l3-DOS
f]''I-Dll

(\hl ~ r'J~~ ~u

REf. [(0 PE 5.. 2&0

- ."."".

...
,

FIELD CHANGE ORDER

f.C .•.••..

.IV.

INSTALLATION PROCERURE CONToR
ADD:

ORIGIN
[3D-DOl.
fOIt-DOIa
fOIt-0].2
E3D-DOIa

•

DESTINATION

LEVEL

JC3],-Ola
JC31-D35
121a-D12
E1l·OOS

1.
2
2
2

c. ON THE (OnpONtNT $It~ Of THE LOGIC BOARI, SOLDER THE SILICON DIODE {2ltS53500}

BETWEEN PINS ~ & 12 Of CHIP LOCATION fait. INSURE THE NEGATIVE OR CATHODE END Of THE
DIODE IS ATTACHED TO PIN Ia. If IN DOUBT AS TO WHICH END IS NEGATIVE OR THE CATHODE,
CHECK lIITH yon TO VERIfY CORRECT POLARITY.

It-!' C~

D. CLOSE fTU AND (ONNECT TO A '71a1a. OPERATE DRIVE AND fTU CHECKING THE fTU·S
ABILITY TO SELECT All HEADS ON THE ,71a1a.
E. LOG feo ON UNIT fCO lOG.
f. UPDATE "AINTENANCE "ANUAL DIAGRA"$ WITH PAGES q. 5 AND Ia.
UPDATE nAINTENANCE "ANUll WIRE LIST.

RatHE ~ Caas
Ia. PARTS & SPECIAL TOOLS:

1. AVAILABILITY:

f(O KIT NUMBER <a,OS37ba}
SEE ASSEMBLY PARTS LIST

KITS DUE BEGINNING APRIL 1.1..1.'60
~utI'V

e· REMOYED PARTS: NIA
,. ATTACHED DoCUr£NTS:

N/A

~ ~~~~ ~

OF ~ ~c..

LdWEJ\ fC... e~D
"DOUIN ~ R-Ot

at' ""'-''1) 8~. Sa- AIetr

M " FO~ ~A-&lI.4~ ~'oci" ~14.lAtf.

...

fiELD CHANGE ORDER
APR 0 4 1980

P,v.

••C.O- NO.

54 280
pAGE

_cv

ASSEMBLY PARTS LIST

2'1553500

DOl.

••

SILICOH£ IIOIE

IJC I~Ci:t<D - rIAl StU

JC~ I

I I :rD :II I'I I :rt-3 I I 1 m3 ' I

t,..,&1:

~l1 ~ Jl'3102f

F3000 l.

(J"A31 0»)

(F30 001) :

/
E

,
ALL fiELD CHANGE ORDERS MUST CONfORM TO CONTROL DATA POLICIES AND STANDARDS

. . . . . . ·.5&

•

CAD . . . .

AUU'·

. . . . . .tI. . ~~""""--I&-_---~J-LI

. .., ""'te." .. --.& ••

..,.....,.._ _.,-_ _ _.:IIUI.....UL.--&.

:I' " •.

Hrl"----=!Ii.,j-L!!ILL..-&~=. " •.

H-+-t-----=L.:::::..=!..1~.....l,..=· " •.

If lJ
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;
til

. -

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~~"

.•,.W!!....@ '0'

106

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•

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@J 110

w
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MIt

a. "'"

1,
..

it
~II

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&)

107

•

::-.

FIELD SERVICE TECHNICAL MANUAL

120,1

:~D~DamD
ll1h~

AIIU .. .,

f 1\11

RHOS BEAD CRASHES.
Bill Peters

16 Bi'

18 Bit

3G B.1

Option or Designator

RMOS

Tt.'C.h Tip

Number RHO S-'l'T-

F.S.O:I.(".,

Maynard

Dat(! 2-28-81

Procenor Applicability

Mgr.ISUjJ.

Date

116JvAi 1 J I I

AslP' C.\/, •• :

0,,1"

Revision

Cron Reference

Due to the very low flying height of the heads and the critical
characteristics of the RMOS packs, it i. recommended that if a
head crash is experienced, you 8hould replace all the heads in
the drive. There i8 no way you can determine with the unaided eye
whether or not the remaining head8 are good or not. This req[uires
a microscope and a thorough knowledge of head construction.
In the event of a crash, the following steps should be
taken:
1.)

Because the RMOS uses a perforated shroud assembly,
you must disassemble the shroud and clean the dec}~
area very thoroughly. Some repeat crashes have bet!n
attributed to contamination left in the drive froln
the original crash.

2.)

Take no chancea. Replace every head when reassembling
the drive. Visually inspect each head for signs o:f
improper assembly or contamination before install:ing.

3.)

Inspect the positioner and magnet for metal particles.
BE THOROUGH IN EVERY RESPECT.

4.)

When drive is reassembled, allow the drive to purge
for a minimum of 30 minutes. Visually inspect the
shroud area before installing a ne" ·scratch pack.

5.)

When the pack has 8pun up for a few minutes and
things look 8table, you can then procede with the
head alignment procedures.

Bere are aome important points to remember:
CDC doe. not recommend head or media cleaning on the

'766.

The tolerancea involved are much more critical than the
RP06 or .tmilar drive ••

,,: r: C:C"'~t='OENTIAL

;'. I. ·'.tinM III i~ ru),)rit:ta.\ ,. : ·1~1::.aI EQuipnl.,,,, Ce·. '1i.'I·m and is In1.·.·,t.·,: lUI,'·'" h'/ i1~. F.dd ~rvi("f'\ (lff, •• ".
, ..... f,.,natltinn on writinq Of .,:,.t'I,vim,. Tech T.n. Sf' ,\~t'lIini\"ation T.·· f: , .1' U·zr.-.I,,·r '1.

PJ!1t

, • "~~c "

"",·".vt

r;allC Revision

PUItI··.ii' ..',

r'ilNi £ D IN U.S.A.

108

D'i~"

tu",n,,",

.=J

FIEI..D SERVICE TECHNICAL MANUAL

Lmo ~DDmD
r;itlc
j1 .. lh",

, AII-

"'"':0:::-·'-'-8-it-::O:l-'S-S-it--=O:--1r-3G- Oi-'-O-+---RM-O-S-----

r-'-2-8,'-'

.105 BEAD CRASHES (Continued)
F.5. OIII(~C Maynard
Bill Peters

I I , I

Processor AppUc.bilitv

IlllVs

Option or Designator

Tl:L"h T.p
Number aMOS-TT-

Date 2-28-81

Mgr./Sup.

D.te

Apstwllal:

Da1e

Revision A
Cross ~eferellce

Due to the 'Burnished media' t.echnqlogy used on these packs,
the normal pack cleaning procedures tend to leave a residue
on the platter surfaces. ~he media requires a apecial power
wash cycle to insure that all the residue i8 removed. Again,
only a keen eye trained to recognize a media defect can spot
a problem by inspecting a pack. CDC recommends a program of
.edia inspection at certain intervals but will not recommend
any cleaning. ~herefore a clean enviornment and proper
storage of media to prevent pack contamination i8 8trongly
8uggested •.
If you have not done ao already, purge all RHOS drives of
any abso111te filter a8semblies with a date code of June 1,
1980 to Of::tober 31, 1980. ~hese •••emblies have been found
to be a source of contamination. Epoxy uaed in the contruction of thIs filter i8 in lIome ca8es chipping off and entering
the air flow. ~he date code i8 found atamped ona yellow
.ticker attached to the filter. ~he part number for the
absolute jfilter is 29-23591.
~he maintainability group

for the RHOS needs to have more
complete reporting of RHOS head crashes. It has been found
that aome RHOS calls, especially if they are repeat crashes,
have been reported on LARS against systems. ~his makes
accurate 'performance statistics difficult at best. The last
page of this ~ech-Tip is a reporting format which should be
used in every instance of a RHOS head crash until further
notice. Send the completed form to: Bill Peters, Corporate
Field Support Group, PK3-2 IRll. We will appreciate your
assi8tance in this very much.
Until thea head crash problem has been resolved, we recommend
that all branches have tbeirRMOS CE and scratch packs
inspected at least once a month by an outside company. This
i8 necessary to eltminate the possibility that our test packs
may be a source of contamination.

I): C CClNt= IDENTIAL

·L.'~."tuc"ment is proprietarv" ':llglt.1 Equiprnt!nt c.;,"S:,U •• 1 ,'II' and i. int...·ncj,·d tor use by its Field $rrvice Orgal,izt»tlon :>nly.
'Ir tn'c"matian on
nr ~I,movinq. TtCh TiP. 5t.'t' Admtni,'r.tion 1'-&.:11 Tip Num',!. 2.

Ihut

_nina
2

tl Page Revision

II Puhlir.il'"'''' Date,
PRINTI 0 IN U.S.A.

• '. "MU~ "

"a,,·nlv.

1 09

FIELD SERVICE TECHNICAL MANUAL

I-------.------.----r-----t-----~DmL'!"~D
~uu~
0 I
iJ I
0 I
0
RHOS
12B,1

Option.ol'Designator

16Bil

: j·lt!

RHOS BEAD CRASHES

lilt'. n

Bill· Peters

:.:\

1BBil

368il

(Continued)
F .5. Oft iCt!

, l
11l1V~ J I
p, o~euo, Applicahl" t \

•

Maynard

Date

. Mgr./Sup.

Date

ApI u ()vat :

Dalc

'Tech Tip .
Number ftMOS'-TT-

2-28-81

Revision

Cr(on .Reference

PLEASE USE THIS FORM TO DOCUMENT RHOS HEAD CRASHES POR
MAINTAINABILITY ENGINEERING IN COLORADO.

*****************************************************************
Branch Offic·e'

' ,.' ,.' .,.

, , , -. , . , .

Cost Center

------------------------------------

------....-

Customer Name_'________________'_'_'_'_'_'____________LARS Log '.___,______
RMOS

Serial'

Pack Serial'

----------------- Date of installation
------------------------Date of failure' .. , ' ... ,..

----------------Suspected cause -------------------------------------------------

Hour Meter reading' ., ,-"..'

S1 te Enviornmen't'

----------------------------------------------,--------

Name of Engineer' . , . ,

Tele.' .

------------------------------------------------------------------------------------------------

Additional comments'" '

SEND TO.

Bill Petera
Corporate Field Support Group
129 Parker Street PK3-2 /lt11
Maynard, Mae ••

c Cr,;4f lOI.NTIAL

' . '
...
.f h)! u ...' hy It~ ("11'1<1 a«'''"'~' t·, ;..
.,•. 1!l,d''''', on writillfl ('.~ . " ;h'. 'I\CI" Tech T,p. 411',' J',I':I'I'lI~" Jf'n" 1,'\ I, II" "'11·,.h··, 2

• f!"

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.t aad h tal"1 ,I

f' .1.1

pf'H'.Jlrn IN If.~.A.
' " , H: "

M27'J,C19V)

110

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