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EK-0TU80-PS-3

June 1983

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Document:	TU80 Magnetic Tape Subsystem Pocket Service Guide
Order Number:	EK-0TU80-PS
Revision:	3
Pages:	96
Original Filename:

OCR Text

EK-0TU8O-PS-003

TU8O

Magnetic Tape

Subsystem
Pocket Service Guide

Issued p'y

RENCE ON
LY
NOT Masn
TAINED

Prepared by Educational Services
of
Digital Equipment Corporation

Ist Edition, February 1983
2nd Edition, August 1983
3rd Edition, June 1987

Corporation.
All Rights Reserved.
Printed in U.S.A.

The reproduction of this material, in part or whole, is

strictly prohibited. For copy information, contact the
Educational Services Department, Digital Equipment

Corporation, Maynard, Massachusetts 01754.
The information in this document is subject to change

without notice. Digital Equipment Corporation assumes
no responsibility for any errors that may appear in this

document

The following are trademarks of Digital Equipment Corporation, Maynard, Massachusetts.

dlilg]ilt|a1

DECwriter

DEC

DIBOL

RSX

DECsystem-10

MASSBUS

UNIBUS

~ RSTS

DECSYSTEM-20 PDP
DECUS
P/OS

VMS

DECmate
DECnet

VT
Work Processor

Professional
Rainbow

VAX

CONTENTS
PREFACE

INTRODUCTION

1.1
1.2
1.3

1.4
1.5
1.6
1.7
1.7.1
1.7.2

.
e
... . .
General ........
Subsystem Overview .....................
TU8O Configuration .....................

Spares Kit ........ .. .. . o,
TOoOIS ot
Applicable Documentation ................
Control Panel ..........
... ... ... .......
Control Panel Description .............
Diagnostic/Maintenance Panel

1
|

5
6
6
7
7
7

Operation ............ccoiiiennia.. 11

On-Line System Diagnostics ........... 12
Maintenance ............ ... 12
Cover Interlock Switch Bypass ......... 13

1.7.3
1.8
1.8.1

INSTALLATION

Transport Configuration Selections ........ 14

2.1

UNIBUS Adapter Module
Installation/Replacement ................. 17

2.2

2.2.1
2.2.2
2.2.3
3

M7454 Preparation and Installation . .. .. 18
CPU Internal Cabling ................. 21
"TUSO External Cabling ............... 23

TROUBLESHOOTING

3.1
3.2
3.2.1
3.2.2
3.2.3
3.24
3.2.5
3.2.6
3.2.7

General ........ ..
Resident Diagnostics .............ooovn...
Corrective Fault Code Matrix ..........
Operator Troubleshooting ..............
Power-Up Health Check ...............
Basic Operator Test Ol ................
Optional Operator Tests ...............
M7454 Resident Diagnostic ............
M7454 Status Checking ...............

26
26
27
27
32
32
33
33
34

CONTENTS

PDP-11 Based Diagnostics ............... 35
PDP-11 Front-End Diagnostic (CZTUW,
CZTUX, CZTUY, CZTUZ) .......... 35

3.3
3.3.1

PDP-11 Data Reliability Diagnostic

3.3.2

(CZTUV) . 36
Operating Instructions for PDP-11-Based

3.3.3

Diagnostics . ... 36
VAX-Based Diagnostic . .................. 37

3.4

VAX Front-End Diagnostic

3.4.1

(EVMBD, EVMBE) .................. 37

3.4.2

VAX Data Reliability Diagnostic

3.4.3

(EVMAA) ... 37
Operating Instructions for VAX-Based
Diagnostics ...........c.
i, 38

REMOVAL AND REPLACEMENT

4.1.6

Tape Deck Components ..................
BOT/EOT Assembly . .................
Tape Cleaner .........................
File Protect Sensor ...................
Take-Up Reel and Hub Assembly ......
Supply Reel and Hub Assembly ........
Air Bearing Spring Guides .............

4.2

Internal (Inside Cabinet)

4.1
4.1.1

4.1.2
4.1.3
4.1.4
4.1.5

Replacements ...........................
Rotating the Tape Deck ...............
Protective Acoustic Cover .............
Supply Reel Motor ....................
Take-Up Reel Motor ..................
Air Bearing Sensor ....................

4.2.1

4.2.2
4.2.3
4.2.4

4.2.5

39
39
42
43
44
45
46
48
48
50
51
54
55

Pneumatic Pump Assembly

4.2.6

(Compressor) . ....ovvviin i 57

Pressure Regulator and Air Filter

4.2.7

4.2.14

Assembly ...... ... ... .. ...
Magnetic Head Assembly ..............
Cooling Fan Assembly ................
Control Panel Assembly ...............
Power Supply ................. e
Read/Write/Servo Module .............
Formatter/Control Module .............
Power Amplifier Module ..............

4.2.15

Top Cover Interlock Switch ............ 75

4.2.16

Capacitor Assembly ................... 75

4.2.8

4.2.9

4.2.10
4.2.11
4.2.12

4.2.13

MODULE LAYOUTS

TU80 REGISTERS

59
60
63
64
65
69
72
14

CONTENTS

1-1

TUS8O Functional Diagram ................

1-2

Tape Transport Cabling Diagram ..........

1-3

Maximum TU80 Configuration ............

FIGURES

1-4

TU8O Tape Subsystem ...................

1-5

TapeDeck .........
... .. ... ... ... ... ...

1-6

Control Panel

1-7

Cover Interlock Switch Bypass Tool

2-1

...........................

.......

Formatter-Control Module ................

Option Selection Components on

2-2

Interface Cabling ........................

2-3

M7454 UNIBUS Adapter Module

2-4

DIP Switch Setting in a Single TU8O

Configuration
2-5

........

........................... 19

Plug-to-Plug I/O Cable Connections ....... 21

2-6

TUS8O Interface Cabling Flowchart

........ 22

2-7

Tape Deck in Maintenance Position

....... 24

2-8

I/O Cable Connections ................... 25

4-1

Tape Deck Components .................. 40

4-2

BOT/EOT Assembly ..................... 41

4-3

Tape Cleaner............................ 43

4-4

File Protect Sensor

4-5

Tape Reel Assemblies .................... 45

4-6

AirBearing .........
... .. ... ... 47

...................... 44

4-77

Tape Deck Functional Positions ........... 49

4-8

Tape Deck Assemblies (Bottom View with
Protective Acoustic Cover Removed)

4-9

...... 50

Supply Reel Motor Assembly ............. 51

4-10

Take-Up Reel Motor Assembly

4-11

Tach Wheel/Sensor Installation ........... 53

........... 52

4-12

Air Bearing Sensor Assembly ............. 56

4-13

Pneumatic Pump Assembly ............... 58

4-14

Pressure Regulator/Air Filter Assembly .... 60

4-15

Magnetic Head Assembly

4-16

Control Panel Assembly .................. 64

4-17
4-18

Voltage Select Card ...................... 67

4-19

DC Voltage Checks ...................... 68

.......... e 61

Power Supply Removal ................... 66

4-20

Logic Modules in Logic Cage ............. 70

4-21

Door Interlock Switch

4-22

(Maintenance View)
Capacitor Assembly

A-1

Read/Write/Servo Module Layout ......... 78

..................... 76
..................... 77

A-2

Formatter/Control Module ................ 79

A-3
B-1

Power Amplifier Module ................. 80
TU8O Register Summary ................. 82

B-2

Bus Address Register

B-3

Data Buffer Register ..................... 83

.................... 83

CONTENTS

B-4

Status Register ...........
... ... ... ...

B-5

Residual Byte Count Register .............

B-6

Extended Status RegisterO ...............
...............

B-7

Extended Status Register 1

B-8

Extended Status Register 2 ...............
Extended Status Register 3 ...............
Troubleshooting Flowchart . ...............

B-9

TABLES

Recommended Spares List (RSL) ..........
Related Documents ......................

Tape Transport Configuration Selection . ...
Single TU80 Address Selection ...........
Address Selection in Multi-TU80
Configuration

.............cccvvuinvn
..

Fault Code Matrix (Operator Test 01) .....

PREFACE

This document is designed to be used by someone trained
to service a TU8O subsystem. Procedures are brief, con-

cise, and support the maintenance philosophy of module
replacement.

The first two chapters provide product overview and

installation information for quick review. Chapter 3 is

troubleshooting information. By using diagnostics and con-

trol panel features you can quickly locate malfunctions.
Chapter 4 provides removal and replacement procedures.
Appendix A provides electronic module layout. This document does

not include programming information,

but

Appendix B does provide register summaries and definitions. There 1s a Troubleshooting Flowchart, which shows

troubleshooting procedures, on the foldout in back of this

document.

Vil

INTRODUCTION

1.1

GENERAL

The TU80 Magnetic Tape Subsystem is a dual-speed,
nine-track streaming tape data storage system. The TUS80
Tape Transport is a fully integrated tape transport, pack-

aged with all its control and power electronics in a standard H9643 cabinet. The transport communicates with a
host system via a shielded interface cable assembly connected to a M7454 UNIBUS adapter, plugged into the

SPC slot of the host CPU.
1.2

SUBSYSTEM OVERVIEW

Figure 1-1 shows the TUS80 subsystem functional block
diagram. Figure 1-2 shows the cabling diagram.
NOTE
You can connect up to four TU8O tape transports to a single host CPU (Figure 1-3). Each

TUS8O interfaces with the CPU through a dedicated UNIBUS adapter module (M7454) and
interface cable assembly.

Refer to Paragraph 2.2 for M7454 installation
and set-up.

INTRODUCTION

M7454
UNIBUS

ADAPTER
MODULE
3

-y

INTERFACE CABLES

anad

FORMATTER/

1 conTROL

—— —®1 MODULE

OPERATOR

CONTROL

PANEL

|
I

POWER

AMPLIFIER

I
I

MODULE

&
—

——

—

!
POWER

SUPPLY

MODULE

-+ - —

CONTROL

—_—

POWER

MECHANICAL

-—eeeoe-ob

1-1
Figure

DECK

MODULE

.z
|
o

— —| *
120/240
vac

TAPE

READ/WRITE

=== SERvo

T_______:

— _—

$
¢

gB:\EAL;%?E‘:‘%R go-0000000

TU8O0 Functional Diagram

MA-0079-82

INTRODUCTION

TOP

[32

|2 |

4 | 4

T o

READ

neap

w6P!
&

| 9!

MAG | wRITE

AsSY

W3P3

1 | ¢

)

Meap

~TTENSTRANS|

MT2

+TREF[

NTLK

+TTENSTRANS|

SENSQOR

COVER

BLK]
[por-B- BLKSLY P3

HEAD

{

ws_

| V!

ERASE

BoTt

MT5

ot catH[i0]

SENSOR

sulTT]

BOT ANO|

[
2
|
PR

5
=

;

NU| 4 |
R

esllio]

|
1/0

ps| }.~_ |

CABLES

RD/A\TI:I/SERVO

Phis

FRMTR/CONT

4 o, 18

I
|

N2 P2

WTP6

wW3p!

CAGE

‘
|

LOGIC

‘

|sid

’

EoTcoL | |

EOT EMIT | 2

DI e

Nul 8

EOT CATH|

NU| 7

EOT

8 N 7 PT] 8

EOT ANO[ 6

SENSOR

AlA2

Pl|S

|p2|P
P2
P,

—

BOT EMIT| 13
Nu (12

AlAl

‘}43_1:3_{:

S
I

WHTSLV

BOT COL| 14

AlA2

EMI

+FREF{

-FREF{

+FTENSTRANS| 2 |2

O—\

TAPE TENSION

-FTENSTRANS[ @ |4]

L@
COOLING

£2

SENSOR_MTI
SLhoVR
Ml

FAN

34 POSN

[ ] wapra

A2AI

| [wars]

.
46,

CONTROL

w2Pi

PANEL

POWER

SUPPLY
——

POSN

5 posN

POSN

3 .____@

MA-00739-83

Figure 1-2

Tape Transport Cabling Diagram

(Sheet 1 of 2)

INTRODUCTION

1999 LINE TACH

Al
B34l

8LK

w3P2

RED

B3P

ARI

W7P2

7 WIRES

92 1a

AMPL. | g

P | PWR

w3 |P7

PNEU.

]
493

[

[ 2

Jui| o

3 POSN
J4

4 POSN

PUMP

MOTOR

<
|

W3P6

6154 3121!

MT3

PEEZEfR g

|FILE PROT COY

§ °

| 5

JFILEPROTEMIT

jagial

4 NV

2 [FILE PROT CATH,

SUPPLY MOTOR

@.___

W3P5

PROTECT
SENSOR

LINE

TACH

FILE

3 MT4

FILE PROT ANO

ASS'Y

874

POWER
CONTROLLER

@_——-———{::}-—MAIN POWER
MA-0079-83

Figure 1-2

Tape Transport Cabling Diagram

(Sheet 2 of 2)

(4)
M7454

ADAPTER

CPU

MODULES

[
TU80

TU80

TU8O

MA-0411-82

Figure 1-3

Maximum TU80 Configuration

INTRODUCTION

1.3

TU80 CONFIGURATION

Figure 1-4 shows the TU80 subsystem basic components.
The transport is compactly mounted in the upper portion

of the H9643 cabinet. Figure 1-5 shows the tape deck.

NOTE
To ease TU8O transport maintenance, the transport deck is mounted on a pivot. The deck can be
rotated from horizontal (operational) position to

vertical (service) position. A special service lock
(tape deck latch) on the left side of the cabinet
under the tape deck, keeps the deck in one of

those positions. (For more maintenance infor-

mation, refer to Chapter 4).
The TUSO has the following variations.
TUB0-AA

120 Vac, 60 Hz

TUSO0-AB

240 Vac, S0 Hz

gmgim‘

TUBO TAPE
TRANSPORT

DA
MODULER

ADAPTE

’

—

wim

(M7454)

EXTERNAL
INTERFACE

CABLES

POWER CORD
& PLUG

874 POWER

CONTROLLER

H9643

CABINET
MA-0077A-82

Figure 1-4

TUS8O Tape Subsystem

INTRODUCTION

POWER
SUPPLY

HEAD
ASSEMB
TOP

BREAKER

COVER

INTERLOCK

SWITCH

CIRCUIT

- SUPPLY

REEL

TAKE-UP

[REEL
FRONT DOOR
LOCK

MA-0408-82

Figure 1-5

Tape Deck

SPARES KIT

1.4

The TU80 CD Kit(PN A2-W0618-10) contains the TU80
Pathfinder (EK-0TUB0-SV), the cover interlock defeat tool,
and all spares. Table 1-1 is a list of field replaceable units
(FRUs) or spare parts on the Recommended Spares List
(RSL). Refer to figures in Chapter4 (Removal/Replacement)
and use the Illustrated Parts Breakdown (IPB) when you try
to locate a particular part or assembly.

1.5

TOOLS

In addition to the Digital Tool Kit and the TUCO1 Tape
Cleaning Kit, you should have BOT/EOT (PN
90-09177-00) markers. You need a special 3 /8 inch socket
set (PN 29-22445-00) to remove the reel motors.
You do not need any other tools or instruments to service
the TUS8O tape transport.
|
However, to install the TU80 you need the following
tools.

5/32 inch allen wrench

3/4 inch combination box and open-end wrench

7/16 inch open-end wrench
9/16 inch open-end wrench
5/16 inch flat blade screwdriver
No. 2 phillips screwdriver

INTRODUCTION

Table 1-1

Recommended Spares List (RSL)

Digital PN

Description

—=29-24210
--29-24211
= 29-24212
«~=9-24213

Tape cleaner assembly
Sensor, file protect
Hub assembly, take-up reel
Motor installation kit*

=~29-25046

Compressor (pump), universal 50/60 Hz

29-24215

Magnetic head installation kit

29-24216

Operator panel assembly

29-24220

Power supply, 60 Hz

29-24221

Formatter/control module

29-24222

Read/write/servo module

==29-24223
~=29-24224
w=29-24227

Power amplifier module
Hub assembly, supply reel
Air filter

~29-24228

Cooling fan

==29-24354

Pressure regulator

Switch, door interlock

29-25397
- 29-24356
- 29-24357
»«709-24358
—29-24359
M7454
29-26372

Sensor, EOT/BOT
Capacitor
Tachometer, 1 line
Air bearing refurbishing kit
Adapter module
Power supply, 50/60 Hz

* Used when replacmg takeup ree and/ or supply reel motor.
T

1.6

CaiD

PEW

DR L

fee

”“"%“"“Mg

APPLICABLE DOCUMENTATION

If you need more information on the TU80 subsystem,
Table 1-2 lists related documents.
Also, use manuals and handbooks appropriate for the
PDP-11 and VAX computer systems and processors.

1.7

CONTROL PANEL

The following paragraphs discuss the control panel,
diagnostic/maintenance panel operation, and on-line system diagnostics.

1.7.1

Control Panel Description

Figure 1-6 shows the TU80 control panel switches and status indicators.

The left part of the control panel contains operator
switches/indicators. The two-digit display indicates a fault
code related to an abnormal operating condition, or a test

code when in diagnostic mode. The right part of the panel
contains switches for running internal diagnostic tests.

INTRODUCTION

Table 1-2

Related Documents

Document/PN

Description

TU8O Field

Provides schematic diagrams for TUSO.

TU80 Magnetic Tape
Subsystem User Guide

Contains functional overview,
installation, operating and programming

(EK-0TU80-UG)

information.

TUS8O Technical/

Contains system functional description,
installation and acceptance procedures,
theory of operation, and maintenance

Maintenance Print Set
(MP01603)

Service Manual
(EK-0TU80-TM)

information.

TURO Pathfinder

Contains detailed troubleshooting

(EK-0TU8O0-SV)

information including troubleshooting
procedures, tests, sub-fault codes.

TURSRO Illustrated

Provides list and illustrations of

Parts Breakdown

replaceable parts.

(EK-0TUS8O-IP)
874 Power Controller

Provides list and illustrations of

Illustrated Parts

replaceable parts.

Breakdown

(EK-00874-1P)

Operator Controls

Switch/Indicator
LOGIC OFF

Function

Switch — When pressed, power is
removed from transport logic circuitry and LOGIC OFF indicator
turns on.

Indicator — When on, indicates a

standby

power condition exists
(power supply on, the cooling fan
starts turning, and transport logic is
off).
If indicator is off and no other indicators are on, then power switch
(circuit breaker) is off (0) or there
is a power supply problem. If indicator 1s off and LOGIC ON indicator is on, all transport circuitry is in
power-on condition and ready for
use.

INTRODUCTION

INDICATOR
\

P\,

MAINTENANCE

PUSHBUTTON

[

—

FILE PRO

SELECT

DIAGNOSTICS

LOGIC

OFF

I_1
I

ON LINE

1
it
—

TEST

STEP

EXECUTE

TWO-DIGIT

LOGIC

UNLOAD

ON
—

N——

LED

RESET J

DISPLAY

—

OPERATOR
MA-0083A-82

Figure 1-6

Control Panel

Operator Controls (Cont)
Switch/Indicator

Function

LOGIC ON

Switch — If pressed when power
switch (circuit breaker) is on (1),
the transport logic and control system 1s powered up and TUS8O is
ready for operation.
Indicator

When

on,

indicates

transport circuitry is powered up

and TUS8O is ready for use.
BOT

Indicator

When

on,

indicates

tape is positioned at beginning-oftape (BOT) marker.
LOAD/REWIND

Switch — If transport is powered on

and

tape

1is

threaded,

pressing

LOAD/REWIND
causes
load
operation to be performed. If tape
is loaded, pressing switch causes
rewind operation to BOT.
UNLOAD

Switch - If tape is loaded at BOT,
pressing UNLOAD causes tape to

unload from take-up reel and tape
path, onto supply reel. If tape is
loaded beyond BOT, it rewinds to

BOT. If tape is threaded, but not

loaded,

pressing

transport

switch

slowly

onto supply reel.

causes

unload

tape

INTRODUCTION

Operator Controls (Cont)
Switch /Indicator

Function

ON LINE

Switch — If tape is loaded, pressing
ON LINE causes TU80 to go on-

line and become accessible by host
system. Press RESET switch to
take TUSO off-line.

Indicator — When on, indicates that
TU80O is in on-line mode. All
and
RESET
except
switches
LOGIC OFF are inhibited.
FILE PRO

Indicator — When on, indicates
absence of write-enable ring in supply reel and write operation is
inhibited. Otherwise, write operation is allowed.

SELECT

Indicator — When on, indicates the
following.

® The address in TU80 and CPU
are the same.

® When the two I/O cable are disconnected, the address decoder
in the transport is functional.
®

Pinl inl/O cables and Pin1 onthe
M7454 are assembled correctly.

® TUBS8O is not in diagnostic mode.
RESET

Switch — When pressed, transport
goes off-line, tape motion stops, and
error status clears. Switch can stop

LOAD or REWIND operation. Also
turns off RESET indicator and clears
diagnostic test conditions.

Indicator — When on, indicates that

TUSO is in fault or diagnostic status.
Two-digit display may contain fault
or termination code,

code.

or diagnostic

INTRODUCTION

Diagnostic Controls

Switch/Indicator

Function

DIAGNOSTICS

Indicator - When on, indicates that
TUS8O is in diagnostic/test mode.
Indicator stays on until you press
RESET.

TEST

Switch — If TU80 has tape threaded but not loaded, pressing TEST
places unit in diagnostic/test mode.

STEP

Switch — In diagnostic/test mode,
pressing
STEP
increments
diagnostic/test sequence numbers
in two-digit display by one, or to
the digit required.

EXECUTE

Switch - In diagnostic/test mode
(with test number displayed), pressing EXECUTE initiates this internal diagnostic test.

CE (customer
engineer)

1.7.2

Switch — If TUO is in diagnostic/
test mode, pressing CE (customer

engineer) and TEST at the same
time recalls an internal diagnostic
routine (Field Service Tests) to aid
a Field Service Representative.

Diagnostic/Maintenance Panel Operation

The TUS8O has internal (resident) diagnostics which can be
initiated through the transport’s control panel. Internal
diagnostics include operator diagnostic tests and Field
Service diagnostic tests (customer engineer tests),
described in Chapter 3.

To get into diagnostic mode and initiate Operator or
Field Service diagnostic tests, use the diagnostic panel as
follows.

1. To recall operator diagnostic tests (01, 02, 03), press
TEST. 01 appears on the two-digit display. Each time
you press STEP, the display number increments by
one. Press EXECUTE to initiate the test you chose.

INTRODUCTION

2. To recall Field Service diagnostics, press and hold CE
and press TEST.
a.

The DIAGNOSTICS indicator illuminates.

b. 00 appears on the two-digit display.
Press STEP.

a. The display number increments by one each time
you press STEP, or increments automatically if
you press and hold STEP. The display can show
00 through 09.

b. To select a test number, use the STEP and TEST
switches. When you press TEST after you press
STEP, the number multiplies by 10.
Example: TEST 39 is required
Step
]
2.
3.
4.

Display
Press CE and TEST.
Press STEP three times.
Press TEST.
Press STEP until 9 displays.

00
03
30
39

Press EXECUTE to initiate the test.

After the fault code appears on the display, you can
recall the sub-fault code by pressing CE. The sub-fault
code is displayed as long as you hold CE.
1.7.3 On-Line System Diagnostics
The TUS8O is used with the PDP-11 and VAX systems.
The TUSO subsystem status and performance can be verified by using PDP-11- and VA X-based on-line diagnostics.
Paragraphs 3.3 and 3.4, respectively, describe these tests.
1.8

MAINTENANCE
NOTE

The TU80 does not need any mechanical and/or
electrical adjustments or alignments for corrective or preventive maintenance.

Maintenance procedures include only regular cleaning of
the tape path components.

INTRODUCTION

1.8.1

Cover Interlock Switch Defeat

When servicing the TU8O, a Field Service Engineer may
have to operate the unit and run diagnostic tests with the top
cover open. To bypass the safety interlock switch, use the

interlock defeat tool supplied in the TU80 CD Kit. You insert
this tool into the interlock latch to keep the interlock switch
depressed, which simulates the top cover closed condition
(Figure 1-7).

Use the interlock tool as follows.
1.

Insert the tool into the slot of the cover interlock.

Turn the tool 90 degrees to keep it locked in the latch
cutouts.

| INTERLOCK

LATCH

| DEFEAT

///////’ i

| TooL (/;;i/

MA-0076-83

Figure 1-7

Cover Interlock Defeat Tool

INSTALLATION
This chapter provides information on how to select and
check the transport-selectable addresses and options, and
install or replace the M7454 UNIBUS adapter module.
2.1 TRANSPORT CONFIGURATION SELECTIONS
During TU80 installation and check-out, check the
formatter/control module for correct setting of the transport address and option selection components that specify
the transport operating status and characteristics.

Table 2-1 and Figure 2-1 identify these features and the
location of the involved components on the formatter/

control module.
NOTE

“Standard” means a standard component set-

ting, good for normal operation in Digital com-

puter systems.

INSTALLATION

Table 2-1

Tape Transport Configuration Selection

Option

Component/Location

Comments

Channel Parity W1 Location 18C
Check

Positions 1 and 2

As shipped (standard) —
Parity bit transferred
with data

Positions 2 and 3

Optional — Use if parity

bit is not transferred
with data

Short Gap

W3 Location 16D

Variable short

Positions 1 and 2

As shipped (standard)

Positions 2 and 3

Optional

gap (0.6 to

0.9 in)

Fixed short
gap (0.6 in)

Long Gap

W4 Location 16C

Variable long

Positions 1 and 2

As shipped (standard)

Positions 2 and 3

Optional

gap (0.6 to
1.2 in)
Fixed long
gap (1.2 in)
Auto Speed

W5 Location 16E

(see Note)

Positions 1 and 2

Optional — Disables
auto speed select

Positions 2 and 3

Formatter

Location 21D

Address O

S1 — off

Transport

Location 21D

Address 0

S2 — off, S3 — off

As shipped (standard) —

Enables auto speed select

As shipped (standard)

NOTE
Jumper W35, Auto speed control — When you invoke

this standard feature, the transport will not automatically select 25 inch per second (ips) mode when
low speed is commanded. Instead, the transport
chooses the optimum speed to match system requirements. If 100 ips mode gives the best throughput, this

mode is used; the same applies to 25 ips streaming and
25 ips start/stop modes. The transport chooses the
operating mode automatically; system involvement is

notrequired. This feature allows the TU80 to run under

standard Digital 1/2 inch tape software, yet, offer the
advantage of streaming. With this option enabled, the

unit responds to a Set 100 IPS command in the normal
manner.

INSTALLATION

ALL SWITCHES

6 7 8 9101112 13 14 15[)5
T
/s L

|
)

MA-0412-82

Figure 2-1

Option Selection Components on
Formatter-Control Module

INSTALLATION

2.2

UNIBUS ADAPTER MODULE

INSTALLATION/REPLACEMENT

The M7454 UNIBUS adapter module is a standard quad-

height module positioned in a small peripheral controller
(SPC) slot on the host computer backplane. The M7454 is

connected to the TU8O transport by a set of internal and
external interface cables (Figure 2-2).

When you have to install the M7454 in the CPU (during
subsystem installation or module replacement), the instal-

lation procedure includes: preparing the M7454 (address
switch checking or setting), installing the M7454 in the
SPC slot, and interface cabling. Refer to the following
paragraphs and figures for the required procedures.

170
INTERNAL

CABLES

(’UNIBUS

ADAPTER
MODULE

/(M745M

7
(;;:))

j\\ o

BULKHEAD

PANELS &

P e, -

LOGIC RACK

CcPU

INTERFACE

&
g

EXTERNAL

_-—‘——-—-g-—‘._g-.-\\

'/ CONNECTORS

(BC17N-24)

TU80
REAR

Figure 2-2

Interface Cabling

AIM7

CABLES

‘

2.2.1

INSTALLATION

M?7454 Preparation and Installation
NOTE

You need to use the CPU Kit (TUS80K-CP) to
perform this procedure.

Remove M7454 module, cables, bulkhead connectors,
and mounting brackets from CPU kit shipping container.
Unwrap and examine them for any damage.

2. Onthe M7454 adapter module, make sure selections are
correct for the UNIBUS address, interrupt vector, and
word burst on a single 10-position DIP switch in location
20C (Figures 2-3 and 2-4).
NOTE

Table 2-2 shows the typical UNIBUS address
and vector for a single TU80 Subsystem
configuration.

When more than one (up to four) TU80 subsystem is installed with the host system, use Table
2-3 to select the UNIBUS addresses and vectors.
NOTE

Switch positions 1 to 7 select vector bits 8 to 2.
Switch position 8 selects two-word or four-word
burst size. Two-word burst size is used for
UNIBUS operation. Switch positions 9 and 10
determine a transport number and the corresponding UNIBUS address.
CAUTION

Check jumpers in location 4F on the module.
Jumpers JP11 (W4), JP12 (W3), JP13 (W2), and
JP14 (W1) select the UNIBUS address range. The
standard starting address is 772522s selected by
JP11 (W4), which is etched on side two of
20M 7454 (M7454).

If another address range is required, cut JP11 and
install JP12 (for address range starting at 772722),
JP13 (777362), or JP14 (777422).

INSTALLATION

/O INTERNAL (FLAT)
REFERENCE

CABLES

EDGE

AND CONNECTORS

SELF-TEST
LED INDICATOR

OFF

20C

o000

OO(Of(:),/

-;W N0mo0 L
1IN

20M7454

M7454

Figure 2-3

M7454 UNIBUS Adapter Module

EXAMPLE: SWITCH 1(BIT 8) IS IN ON POSITION

VECTOR BITS

OFF
SWITCH

POSITIONS

VECTOR

)

ADDRESS

SELECT

SELECT
BURST

SIZE *
*ON-2WORDS
OFF -4 WORDS

SHR-0343-87

Figure 2-4

DIP Switch Setting in a Single TU80
Configuration (Address 172522, Vector 224).

INSTALLATION

Single TU80 Address Selection

Table 2-2

Unit
0

Address

Vector

Switch 9

Switch 10

1725224

2244

F224¢

Address Selection in Multi-TU80 Configuration

Table 2-3

Transport Unit
0

1
2

9416

Address

Vector

Switches

Configuration

1 (unitO)

172522g

224g

F5221¢

9416

772526g

float*

off 2 (units0,1)

float*

off

float*

off

off 4 (units0,1,2,3)

F5261¢

172532g

3 (units 0,1,2)

F55A1¢

172536g
F55Eq¢

* Floating vector — 300 to 700g.

3. Remove G727 bus grant card from desired SPC slot.
Remove (cut CAl to CB1) nonprocessor grant (NPG)
jumper from the backplane of the same SPC slot.

Plug two internal ribbon cables (not keyed connectors)
into the J1 and J2 edge connectors on M7454 module

(Figure 2-3). Plug cable with male external connector
into J1 on the board, and cable with female external

connector into J2. To correctly connect all I/O cable

plugs, follow Figure 2-35.

Carefully insert M7454 module into SPC slot.
NOTE

Ifyou are replacing the M7454, perform only the
necessary steps from the following paragraphs.

INSTALLATION

FEMALE
s3

[HosT CPUTTM

T 1 smieLDeD

M7454 | P3

)

-RFACE

CABLES,

[

PANELS

A LE

FORMATTER/

CONTROL

{MODULE

J2[

I TAPE TRANSPORT

FEMALE

MALE

|
i

| P5

FEMALE ,

!
MA-0409-82

Figure 2-5

Plug-to-Plug 1/0 Cable Connections

2.2.2

CPU Internal Cabling
Examine the CPU for compliance with FCC installation
specifications. According to FCC requirements, the CPU

should have the I/O bulkhead connector frame at the bottom rear of its cabinet.

Then, follow the applicable procedures (A or B) shown

in Figure 2-6.
Procedure A
I.

Install I/O panel (PN 74-26907-12) on CPU’s 1/0
bulkhead frame at bottom of CPU cabinet (Figure
2-6, Procedure A). Secure I/0O panel with two screws.

Route internal I/O ribbon cables from M7454 module through CPU cabinet to CPU frame. Then, insert

cable connectors into slots on 1/0O panel.

Go to Paragraph 2.2.3 and perform external interface
cabling.

NOTE

Do not chafe the internal cables against other

modules and chassis parts.

INSTALLATION

FCC
COMPLIANT
CcPU?

IS CPU

READY?

(7454 AND |/O

PROCEDURE B

PROCEDURE A

PANEL INSTALLED)

SPC SLOT

INSTALL M7454 IN

l INSTALL M7454 IN

!
INSTALL /O PANEL

SPC SLOT

PN 71-26407-12 INTO

I/0 FRAME

INSTALL /O PANEL

PN 74-27292-01
INSTALL THIS
ASSEMBLY

PN 74-26407-12 ON
CPU BULKHEAD
FRAME

'ON CPU RACK

RQUTE RIBBON /0O
CABLES THRU
CABINET AND INSERT

CABLE CONNECTORS
INTO I/0 PANEL
SLOTS

CONNECT EXTERNAL
SHIELDED INTERFACE

' CABLES TO 1/0 PANEL
CONNECTORS

CONNECT EXTERNAL
CABLES TO TU80

Figure 2-6

TURO0 Interface Cabling Flowchart

Procedure B

1. Mount 1/O panel (PN 74-26407-12) on I/O frame
(PN 74-27292-01). Secure with two screws (Figure
2-6, Procedure B).

2. Install I/O frame (with I/O panel) on CPU rack. Find
location in CPU rack that will best accommodate
internal and external interface cabling.
NOTE

Digital recommends locating the 1/0 frame at

the bottom rear of the CPU cabinet.

3. Repeat steps 2 and 3 above.

INSTALLATION

TU80 External Cabling
NOTE
You need to use the Accessory Kit TUSOK-AC

to perform this procedure.
Use allen wrench to open rear door.
NOTE
To check the I/O cables in the TU8O, refer to
Figure 2-7.
.

Route external shielded interface cables (PN BC17N-12)

from TU8O to CPU (Figure 2-2).
NOTE
In configurations with three or four TU80s on

one CPU, you can use 24 ft cables (PN BC17N-24).
On CPU side, insert external interface cables into keyed
bulkhead

connectors

the

CPU

I/O

frame

(or

bracket). This step connects the cables with the internal
UNIBUS cables. Secure each plug with two screws

(Figure 2-8).

Close rear door.

INSTALLATION

OPERATING POSITION

TAPE DECK

’

LATCH

TAPE DECK IN

MAINTENANCE

/ > POSITION

MA-0098-82

Figure 2-7 Tape Deck in Maintenance Position

INSTALLATION

)

1/0 PANEL

(74-26407-12)

ROUND
\ INTERFACE
CABLE

RIBBON 1/0

CABLE

1/0 BULKHEAD

FRAME (CPU RACK)

1/0 PANEL

(74-26407-12) 7]

. 1/0 FRAME
- (74-2729201)

MA-0109-82

Figure 2-8

1/0 Cable Connections

TROUBLESHOOTING
3.1

GENERAL

Paragraph 3.2 describes internal (resident) diagnostics;
Paragraphs 3.3 and 3.4 respectively, describe the PDP-11

and VAX on-line diagnostics.

When you report to the site, get all the available information from the operator and operating system. You
should consider fault codes, the frequency at which they
occur and, if possible, the operation in progress at that
time before executing diagnostics. If the fault is intermittent, information from the operator and operating system
may be instrumental in directing you to the appropriate
test to duplicate the fault condition.
3.2 RESIDENT DIAGNOSTICS
TUS8O0 resident diagnostics consist of operator diagnostics
and Field Service diagnostics.
NOTE

Make sure that the TU80 power cord is plugged
in, and the transport is energized (power switch
ON) before you start any diagnostic routine.
The diagnostic tests designed into the TU8O are off-line
tests initiated through the control panel. There are no
built-in on-line diagnostics; however, the host CPU can
monitor TU8O status through the Get Status command. A
Channel Loopback command is also provided to exercise
the TU8O’s formatter logic.

Although on-line diagnostics are not part of the TUS80,
the control microprocessor tests for many operational fault
conditions while it runs on-line. These conditions are indicated on the control panel display as fault codes. The
RESET indicator lights to indicate the fault condition and
the control panel displays the approprite fault code.

TROUBLESHOOTING

3.2.1

Corrective Fault Code Matrix

When a trouble call is received from the site, Field Service
personnel should consult the fault code matrix (Table 3-1)
and corresponding corrective action tables in the TUS80
Pathfinder EK-0TU80-SV (supplied in the CD kit). These
tables help Field Service personnel determine if operator
action (A, B, or C) is required. If the fault persists after
appropriate operator action, consult the tables for a list of
FRUs to take to the site.

The fault code matrix lists all malfunctions or fault
codes, and assemblies which may cause the fault condition.
This table is designed to provide a list of related assemblies
before you report to the customer site. Assemblies listed
under individual malfunction or fault codes are arranged
in a “most probable fault” order. In addition to listing
assemblies, the table may direct the Field Service
Representative to ask the operator to perform Operator
Diagnostic Test 02 or Test 03.

When on-site, consult and use the TUS80 Pathfinder
(troubleshooting procedures and diagnostic tests) to isolate
and correct the malfunction.

3.2.2

Operator Troubleshooting

Before you run any tests, do the following steps to isolate

an easily correctable external malfunction.

1. Make sure the tape has a BOT marker.

2. If a write operation is to be performed, make sure the
tape reel has the write-enable ring installed.
3. Make sure the tape path is clean.

4. Make sure the power switch is on (1).

5. In case of power failure, make sure the power controller circuit breaker 1s on.

6. Make sure the top cover door is closed and latched.
NOTE

If the host computer reports data (read/write)

errors, “first-aid” action is to clean the tape
path.

TROUBLESHOOTING

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TROUBLESHOOTING

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TROUBLESHOOTING

Power-Up Health Check

3.2.3

This self-test diagnostic checks ac power, and the control
panel’s and major logic modules’ functionality.
To start the health check, press the LOGIC ON push-

button (assume the power switch is on).
The two-digit display should momentarily show 00, the
LOGIC OFF indicator should go off, and the following

indicators should go on momentarily: BOT, RESET, ON
LINE, DIAGNOSTICS and SELECT. The LOGIC ON

and FILE PRO indicators should go on and stay on.
NOTE

If a fault code appears on the display, press
RESET and LOGIC OFF to clear the display.

Then press LOGIC ON again to repeat the
Health Check.

If the fault code reappears, refer to the TU80
Pathfinder for on-site troubleshooting procedures and Field Service diagnostic tests to isolate the failure.

3.2.4

Basic Operator Test 01

This test checks basic transport functions and tape motions
including BOT/EOT tape motion, read data, and write
data. Use a write-enabled, known good quality tape, for
this test. The test takes about 10 minutes to complete (with
2400 foot tape).

Pre-Test Conditions

1. Power switch and LOGIC ON are on (power-up
health check is successful); digital display is blank.
2. Tape is threaded through tape path and onto take-up
reel.

3. Tape is not loaded.

4. Top cover is closed and latched.

TROUBLESHOOTING

Test Procedure

Press RESET.

2. Press TEST on control panel’s diagnostic portion.
a. DIAGNOSTICS indicator lights.
b. Digital display indicates O1.
3. Press EXECUTE.

a. Test starts with display panel incrementing from
00, 11, 22, through 99. Make sure all numerical
display segments are functioning.

b. Make sure all indicators except LOGIC OFF,
BOT and SELECT are lit.

Test Successful

If the test completes, the TU80 performs a REWIND/
UNLOAD operation and the digital display indicates 00;
the RESET indicator is lit.
Test Unsuccessful

If the test is unsuccessful, the diagnostic program halts and
the display shows a numerical code; the RESET indicator
is lit. Record this number and refer to the TUS0
Pathfinder for further instructions.
3.2.5

Optional Operator Tests

The optional tests are 02 and 03. The user may perform
them on your request.

Test 02 checks tape tension characteristics. Test 03
checks operation of the velocity servo loop and the take-up
motor/tach assembly.

When Test 01 calls for Test 02 or Test 03 to be execut-

ed, refer to the TU80 Pathfinder for more information.
3.2.6

M7454 Resident Diagnostic

The M7454 UNIBUS Adapter Module performs its own

resident diagnostic routine at system power-up. To run this

diagnostic, turn the CPU circuit breaker off and on.
The M7454 diagnostic resides in the on-board program-

mable ROM and checks the M7454 module only, without
tape motion or interface testing. The diagnostic checks the
M7454’s microprocessor, sequencer, data paths, and buffer area. The lit LED on the module indicates a successful
test.

TROUBLESHOOTING

3.2.7

M7454 Status Checking

3.2.7.1

TU80

Turnkey

Configuration

—

When

the

M7454 (and TUS8O) fails during new system configuration
(PDP-11 or VAX), the host configures around the TUS&O,
not recognizing it. The computer console terminal displays
the appropriate error message.

3.2.7.2
1.

TU80 Add-On Configuration

If a TU8O i1s added to a PDP-11 system, an operator

must reconfigure the host system by using an applicable SYSGEN routine. If the M7454 fails during
SYSGEN, the host cannot access the TU80 and the
console terminal displays the appropriate error
message.

If a TUS8O is added to a VAX system, the host automatically configures the unit into the system. If the
M7454 fails at that time, the host cannot access the
TURO, and the terminal displays the appropriate
message.

3.2.7.3

On-Line Failure — If the M7454 fails during normal on-line operation, the host loses communication link
with the TU8O. The error message is entered in the system

error log. When the operator tries to recall the TU8O, the
terminal displays the appropriate error message to indicate
the “not found” status of the device.
To check TUS8O operating status and localize the failed
module, reset the TU80 unit and perform the host system
power-up. Then, place the TU8O on-line and try to access
the transport through the host. If the fault condition persists, replace the M7454 module.

TROUBLESHOOTING

3.3

3.3.1

PDP-11-BASED DIAGNOSTICS

PDP-11 Front-End Diagnostic (CZTUW,

CZTUX, CZTUY, CZTUZ)
This diagnostic is a four-part complex test that checks the
subsystem in all basic operating modes, and tests the interface bus, 1/0 silo and TU8O transport logic.
CZTUW
TST : 001 Initialize 1
TST : 002 RAM test

TST : 003 Command reject test
TST : 004 Write characteristics test
TST : 005 Volume check
TST : 006 Completion interrupt test
TST : 007 Basic packet protocol test

TST : 008 Non-tape motion command test
TST : 009 DMA memory addressing test
TST : 010 Initialization after write characteristic test
TST : 011 Basic write subsystem memory test
CZTUX

TST : 001 FIFO exercizer test
TST : 002 Initialize 4 test

TST: 003 Off-line reject and rewind test
TST : 004 Basic write data test

TST : 005 Basic read data (forward and reverse) test
TST : 006 Manual intervention test
TST : 007 Configuration typeout test
TST : 008 Scope loops test
CZTUY

TST : 001 Space records test
TST : 002 Rereads test
TST : 003 Write data retry test
TST : 004 Write tape mark test
CZTUZ

TST : 001 Write tape mark retry test
TST : 002 Skip tape marks test
TST : 003 No-op and initialize test

TST : 004 Erase and operation incomplete test
TST : 005 Test of operation at EOT test
TST : 006 Function tuning test

TROUBLESHOOTING

PDP-11 Data Reliability Diagnostic (CZTUYV)

3.3.2

This test simulates a typical customer operating environ-

ment and checks data integrity in both start/stop and

streaming modes. It is mainly a data confidence test.
Data Reliability Program Tests
Test 1 :
Test 2:

Test3:

Test4:
Test 5:
Test 6:

Basic functions
Data reliability

Streaming test

Write compatability /write utility
Read compatability/read utility
Operator selected sequence

NOTE

Refer to the diagnostic listing for program con-

trol flags.

Operating Instructions for PDP-11-Based

3.3.3

Diagnostics

Load XXDP+ monitor.
a.

Enter date.

Answer hard core questions.

50 Hz? Type Y or N.

LSI? Type Y or N.

This is XXDP+, type H or H/L for details (help
file).

[Receive XXDP+ prompt (dot)]

3. Enter R (space) program name (CZTUV
CZTUW, CZTUX, CZTUY, or CZTUZ).

The operator entry should look like:

("R ZTUV?]
4.

Receive DR> prompt.

5. Enter the appropriate command. For example, to
start the test type:
DR>STA

TROUBLESHOOTING

6. Change HW(L)? Type Y to run the diagnostic.
7. Change SW(L)? Type Y or N.
NOTE

Refer to the diagnostic listing for specific pro-

gram problems and instructions.
No hard errors are allowed.
Hardware Parameters

The following are TU80 base address and vector
assignments.

TSSR ADDRESS (172522)?
VECTOR (224)?

Command example:

STA/TES:2/FLA : IDU : LOE

Command example

Start test 2, inhibit dropping unit

meaning:

and loop on error

Software Parameters

Refer to diagnostic listings.

3.4 VAX-BASED DIAGNOSTIC

3.4.1 VAX Front-End Diagnostic (EVMBD, EVMBE)
These tests check the subsystem in all basic operating

modes and test the TUSO transport logic, interface bus,

and 1/0

silo.

3.4.2 VAX Data Reliability Diagnostic (EVMAA) subThis check is designed to throughly check out the tape
system. It allows the operator to test the TU80 on-line
without bringing the system down.

The data reliability test consists of the following.
Test 1:
Test 2:
Test 3:
Test 4:
Test 5:
Test 6:

Qualification test
Qualification test
Data reliability test
Multi-drive test
Conversation mode test
Streaming test

TROUBLESHOOTING

3.4.3

Operating Instructions for VAX-Based

Diagnostics
1.

Load the Diagnostic Supervisor (ECSAA, ENSAA, or
ESSAA)

NOTE

Use ECSAA on VAX 11/750s.
Use ESSAA on VAX 11/780s.
Use ENSAA on VAX 11/730s.
2.

Attach and select a device to be loaded in one of two
ways:

Prompt mode

DS> ATT DW7XX HUB DWO
DS> ATT
Device Type? TS11

Device Link? DWO
Device Name? MSAO

CSR? 772520*
Vector? 224

BR? 5

DS> SEL. MSAO
b. Explicit mode
DS> ATT DW7XX HUB DWO
DS> ATT TS11 DWO MSAO 772520 224 5
DS> SEL MSAQO

Load and start the diagnostic in one of two ways:
a.

Example 1
DS> Load EVMAA (or EVMBD, EVMBE)
¥

DS> Start/Switches
b.

Example 2

DS> Run EVMAA (or EVMBD, EVMBE)/

Switches

No hard errors are allowed.
NOTE

Refer to the diagnostic listing for control

flags.
*

CSR address (TUS8O starting address is 772522)

REMOVAL AND

REPLACEMENT

This chapter describes removal and replacement procedures for TU80 components listed in the field replaceable
unit (FRU) table (Table 1-1). Each procedure also names a
test to perform which checks the replaced module.
Paragraph 4.1 describes the FRUs located on top of the

tape deck. Paragraph 4.2 describes FRUs inside the cabinet and accessed only in the maintenance position.
TAPE DECK COMPONENTS

4.1

While you replace the tape deck components, refer to
Figure 4-1 as well as applicable figures. All these components can be accessed easily when the TU80 top cover is

open.

4.1.1

BOT/EOT Assembly

Removal

1. Remove magnetic head dust covers by pulling them
straight out.

2. Disconnect W3P1 plug from BOT/EOT sensor.
Mounting screw is under cable (Figure 4-2).

3. Remove mounting screw from assembly and lift off tape
deck.

CAUTION

Do not loosen or remove phillips screw on

top of assembly. This may cause misalignment.

REMOVAL AND REPLACEMENT

DUST

TAPE

REAR

SUPPLY (FILE)

CLEANER

AIR

REEL

BEARING

EOT/BOT
SENSOR

MAGNETIC ~ AIR
BEARING
HEAD

POWER

SUPPLY

MAGNETIC

CIRCUIT

NEAD

ASSEMBLY
TOP

COVER

BREAKER

'
7.

INTERLOCK

SWITCH

e~ SUPPLY
| REEL
r TAKE-UP
|

REEL

FRONT DOOR
LOCK

MA-0033-83

Figure
4-1

Tape Deck Components

REMOVAL AND REPLACEMENT

EQOT/BOT
ASSEMBLY

MA-0458-82

Figure 4-2

BOT/EOT Assembly

Replacement

NOTE
You must replace any defective sensor as a complete assembly.

Position assembly in its place on tape deck and install
and slightly tighten flat-head mounting screw.

Thread a tape onto take-up reel and adjust BOT/EOT
assembly so it is parallel to tape path. Sensor positioning
is not critical.

Tighten mounting screw.

Reattach W3P1 plug to assembly connector as shown
in Figure 4-2. If excess cable exists, pull excess under
tape deck.
CAUTION
Make sure plug is positioned on correct pins.

Install dust covers.

REMOVAL AND REPLACEMENT

Verification Check

If available, use a 600-foot reel of tape (such as
PN 29-22020) with properly installed BOT/EOT

markers to reduce test time.

NOTE

. Install reel of tape onto supply hub and thread tape so
BOT marker is located before BOT/EOT assembly.

Perform LOAD operation and observe that tape loads
and positions itself at BOT marker (BOT indicator
lights) to check BOT sensor operation.

. Execute Field Service Test 44 to verify EOT sensor
operation.

Unload test tape.

4.1.2

Tape Cleaner

Removal

1. Remove dust covers from magnetic head assembly.
Loosen two pan-head mounting screws and remove

tape cleaner assembly from tape deck (Figure 4-3).

~ Remove screws, lockwashers, and cover plate from
blade housing.

Slide platform mount out from tape cleaner.
NOTE

You must replace defective tape cleaner as a
complete assembly.

Replacement

Inspect cleaner blades for damage. If blades are
chipped or damaged, replace entire assembly.

If blades are not damaged, clean platform and reinstall. When you install platform, make sure flanges are

positioned so platform fits firmly inside tape cleaner.

3. Install cover plate, two washers and mounting screws.

4. Position assembly onto guide pins on tape deck, and
tighten screws.

Reinstall dust covers.

Verification Check
No functional checks are necessary.

REMOVAL AND REPLACEMENT

MOUNTING

—*]

SCREW

TAPE CLEANER

ASSEMBLY

MA-0081-83

Figure 4-3

4.1.3

Tape Cleaner

File Protect Sensor

Removal

Remove tape reel from supply hub.

Remove supply hub (Paragraph 4.1.5).

Remove four mounting screws and file protect sensor

cover plate from tape deck (Figure 4-4).
4.

Remove the phillips mounting screw and washer
securing the file protect sensor to the tape deck
(Figure 4-4).

Detach connector W3P6 from sensor and discard
Sensor.

Replacement

NOTE

File protect sensor positioning is not critical.

Place sensor on tape deck as shown on Figure 4-4, and
secure it with mounting screw and washer.

Attach W3P6 cable plug to sensor pins.

Reinstall sensor cover plate and secure to tape deck
with four mounting screws.

Verification Check
Perform power-up troubleshooting procedure 1003.

REMOVAL AND REPLACEMENT

ALIGN FLUSH WITH
TAPE DECK CUTOUT

W3P6

PLATE

MOUNTING
SCREW HOLES
MA-0464-82

Figure 4-4

4.1.4

File Protect Sensor

Take-Up Reel and Hub Assembly

Removal

1. Remove four mounting screws from take-up reel hub
cover and remove cover from hub assembly (Figure
4-5).

2 Remove three allen screws, lockwashers, and plain
washers which secure reel to motor shaft assembly.
NOTE

Do not remove phillips screws.

3. Remove take-up reel from transport.
Replacement

CAUTION

If you are installing new reel, inspect reel edges

for burrs or cracks that could cause tape
damage.

1. Perform above removal procedure in reverse (position
take-up reel on transport; use three allen screws, lockwashers, and plain washers to secure reel to shaft
assembly; etc.).

REMOVAL AND REPLACEMENT

TAKE UP

REEL COVER

HUB COVER
N
A

ae— MOUNTING

SCREWS (3)
REEL MOUNTING
HARDWARE

TAKE UP

FOR COVER
REMOVAL

R
y.fl

Figure 4-5

CUT-OUT

SUPPLY REEL
HUB ASSEMBLY

Tape Reel Assemblies

Verification Check

Manually rotate tape reel to make sure reel does not
contact tape deck.

Load known good reel of tape and observe reel during
tape motion. Tape should not contact top reel flange.

4.1.5

Supply Reel and Hub Assembly

Removal
¥

1.
2.

Press center button on hub to unlatch it.
Locate slot opening on periphery of reel cover. Insert

small blade screwdriver into slot (cut-out) and twist to
unsnap cover from hub assembly (Figure 4-5).

REMOVAL AND REPLACEMENT

Place hub assembly in latched position by depressing
cam carrier,

CAUTION

Make sure hub is latched before you proceed

with further removal steps. Otherwise, parts

could be lost due to unnecessary disassembly.

Remove three large shoulder mounting screws from
cam carrier. You can then remove hub assembly from
tape deck (Figure 4-5).

Replacement
1.

Position hub assembly onto motor shaft assembly and

secure with three large shoulder screws.

Install reel cover on face of hub assembly and snap

securely.

Verification Check
l.

Mount tape reel onto hub assembly. Reel should
mount easily onto hub and against bottom flange.

2. Latch reel onto hub. Make sure reel is secure.

3. Load known good quality tape and observe reel during tape motion. Tape should not contact top reel
flange.

With tape threaded, but not loaded, execute Operator
Diagnostic Test O1.

4.1.6

Air Bearing Spring Guides

NOTE

Replacement parts for air bearing assembly are

contained in a kit (PN 29-24359) which includes
two spring guides, a transducer (sensor), and
small and large O-rings. If a spring guide has to
be changed, replace both guides at same time.

REMOVAL AND REPLACEMENT

Removal

. Remove head dust covers from tape deck.
2.

Remove two phillips head screws that secure spring

guide and a guard to bearing housing (Figure 4-6).
3.

Remove spring guard and a guide from housing.

Repeat steps 2 and 3 to remove other spring guide.
Replacement

Place new spring guide (refer to Table 1-1 for guide’s
part number) and a guard into bearing housing. Holes
for mounting screws provide positive alignment for
both parts in housing.

Secure assembly with two phillips head screws.

Repeat steps 1 and 2 to replace second spring guide.

Reinstall head covers on tape deck.
Verification Check

With tape threaded, but not loaded, execute Operator
Diagnostic Test O1.

Examine tape for any tape edge damage.

BEARING
HOUSING

SPRING

GUIDE

> @

SPRING

NOTE

THE FRONT AND REAR SPRING GUIDES

ARE NOT INTERCHANGEABLE.
MA-0459-82

Figure 4-6

Air Bearing

REMOVAL AND REPLACEMENT

4.2

INTERNAL (INSIDE CABINET)

REPLACEMENTS

Refer to Figures 4-7 and 4-8 as well as applicable figures
when you access and replace tape transport components in
the cabinet and/or mounted on the bottom of the tape
deck. Appendix A contains layouts of the formatter/
control, read/write/servo and power amplifier modules,
with all cable connectors called out.

Perform all replacements described hereafter with the

tape deck in its service (vertical) position.

With the tape deck in the vertical position it is easy to
service and repair any transport part or module.

The transport has a service release lock (tape deck latch)

(Figure 4-7) which secures the tape deck in either horizontal (operational) or vertical maintenance position.
4.2.1

Rotating the Tape Deck

I. Use a 5/16 inch allen wrench to open front and rear
doors. Release tape deck pawl fastener.

2. From front, reach under tape deck (Figure 4-7) and
locate tape deck latch under tape deck on left side
panel of cabinet.

3. Release latch as follows.

a. Gently lift or press tape deck to remove pressure
from latch ring.

b. Pull latch ring and keep released.

4. Keep latch ring released with one hand and tilt tape
deck up with other hand until deck is in full vertical
(maintenance) position.
NOTE

Listen for a click which indicates tape deck is
snapped in service position.
CAUTION

Be sure not to snag control panel cable or any
other cable in cabinet.

5. To return tape deck to operating position, pull on latch
ring, release tape deck latch, and then tilt deck down
to horizontal position until latch 1s engaged again.

REMOVAL AND REPLACEMENT

POWER

MAGNETIC

CS;J:ESTT
S~

HEAD

TOP

ASSEMBLY

INTERLOCK

\\\\

BREAKER

| supPLY

SWITCH

, ;A;léf upP

%
=

#im

ALY . [9)

JEY;

)

FRONT DOOR
LOCK

OPERATING
POSITION
O

RELEASE

TAPE

DECK LATCH

~/5=/ TAPE DECK IN
b e MAINTENANCE

MAINTENANCE
POSITION
MA-0034-83

Figure 4-7

Tape Deck Functional Positions

REMOVAL AND REPLACEMENT

4.2.2

Protective Acoustic Cover

Removal

I. With tape deck in maintenance position, detach two
pneumatic tubes from nipples on air filter plenum
box. Mark tubes for proper replacement (Figure 4-8).
2.

Release cover mounting screws. Remove cover.

Replacement

Place acoustic cover in place so that you can route
pneumatic tubing through feed-through holes.

2. Tighten cover mounting screws.

3. Reattach pneumatic tubes to air filter box. Make sure
IN and OUT tubes are connected to proper nipples.
4. Return tape deck to normal operating position.

PLENUM

PLENUM/FILTER

TUBES

LOGIC

L% cAPACITOR

CAGE

TAPE

POWER

DECK

AMPLIFIER

LATCH

MODULE

COMPRESSOR

REEL

MOTOR

PLENUM

TUBE

TM 1000-LINE

TACHOMETER

;;ga

SUPPLY
REEL

MOTOR

/t)

CARDTM]
CAGE

TAPE DECK \TAPE DECK
PLENUM

TM COOLING

POWER

SUPPLY

LINE

TACHOMETER

FAN
MA-0431-82

Figure 4-8

Tape Deck Assemblies (Bottom View with
Protective Acoustic Cover Removed)

REMOVAL AND REPLACEMENT

4.2.3

Supply Reel Motor

Removal
NOTE

Supply reel motor assembly is not supplied as a

part of FRU kit. Instead, you must remove

1000-line tach on take-up reel motor assembly
spare and use take-up motor as replacement for
supply reel motor.

1. Remove supply reel and hub assembly as described in
Paragraph 4.1.5.

2. Turn off power switch and unplug power cord.

3. With tape deck in maintenance position (Paragraph
4.2.1), remove protective acoustic cover (Paragraph
4.2.2).

4. Detach BIP1 connector from J3 plug on power
amplifier module (Figure A-3).

5. Remove four mounting screws and tach cover from
motor (Figure 4-9).

Detach W3P5 connector from tach sensor on motor.
NOTE

This connector is not keyed. Mark it for proper
replacement.

SUPPLY REEL

MOTOR

MOUNTING
PLATE

SCREWS (3)
SENSOR
MOUNTING
TACH WHEEL
AND SET SCREWS

TACH

COVER

MOUNTING

SCREWS (4)
MA-0461-82

Figure 4-9

Supply Reel Motor Assembly

REMOVAL AND REPLACEMENT

Remove four mounting screws that secure motor to

rear of tape deck. Carefully remove motor from
transport. Use 9/16 inch extender tool if necessary.
NOTE

You must replace motor tach and sensor on a
new motor assembly. You must replace entire

assembly as a unit.

Continue with motor disassembly and removal of one-line
tachometer (Figure 4-9).
8.

Remove mounting screw and one-line sensor from

mounting plate on motor. Retain for re-use.

Loosen two set screws and remove tach wheel from
motor shaft. Retain for re-use.

10.

Remove four screws on mounting plate and remove

plate. Retain for re-use.
11.

Disassemble spare take-up reel motor assembly

(Figure 4-10) as follows:

a. Remove two mounting screws and tach cover from
washer assembly.

b. Loosen two screws and remove 1000-line tach sensor from motor (reel) shaft and tach wheel.
c. Loosen set screw and remove tach wheel from
motor shaft.

TACH

SENSOR
TACH COVER

TAKE UP

REEL MOTOR

/\r%

SENSOR MOUNTING

SCREWS (2)

COVER MOUNTING
SCREWS (2)
MA-0465-82

Figure 4-10

Take-Up Reel Motor Assembly

REMOVAL AND REPLACEMENT

Replacement

Install one-line tachometer on new motor as follows.

Place mounting plate (from supply reel motor —
removal step 10) onto new motor and secure with
four mounting screws.

Install old one-line sensor and tach wheel (removal
steps 8 and 9) onto new motor mounting plate and
shaft, and adjust according to tolerance requirements listed in Paragraph 4.2.3.1 (Figure 4-11).

CAUTION
When you install

a motor, make sure no loose

wires are between motor mounting plate and

tape deck.
2.

Position replacement motor on rear of tape deck so

B1P1

cable extends to right of motor assembly.

Secure motor to deck with four mounting screws.
3.

Connect BI1P1 cable to J3 on power amplifier module

(Figure A-3).
Connect W3P5 cable to tach assembly on motor.
5.

Position tach cover on motor and secure with four
mounting SCrews.

Replace protective cover (Paragraph 4.2.2). Return

tape deck to operating position.
7.

Perform supply reel and hub assembly replacement
procedure (Paragraph 4.1.5).

WIRES OF
CONNECTOR SHOWN
FACING AWAY FROM
REEL MOTOR

~—1

0.030 +.005"

}.
TACH
WHEEL

0+OO1

TACH

SENSOR
MOUNTING

MOUNTING

PLATE

PLATE
MA-0080-83

Figure 4-11

Tach Wheel/Sensor Installation

REMOVAL AND REPLACEMENT

Verification Check
1.

Check hub assembly (Paragraph 4.1.5).

With tape threaded, but not loaded, execute Operator
Diagnostic Test O1.

4.2.3.1

Tach Wheel/Sensor

Installation
1.

Insert tach wheel on motor shaft. Position tach for

0.030 £ 0.005 inch clearance between tach and sensor
mounting plate (Figure 4-11).
Install sensor on mounting plate and position for 0.150
+ 0.01

inch clearance between sensor and tach.

Tighten sensor mounting screw.
Verification Check
1.

Verify that connector W3P5 is attached to the supply
motor tach sensor pins.
Turn

the

drive

power on

before installing the

tachometer cover.
.

Using a voltmeter, probe the top pin of connector

W3P5 and verify that +5 volts (logical high) is present
when the reflective strip on the tachometer wheel i1s

not aligned with the sensor. Now align the reflective
strip with the sensor by turning the tachometer wheel

by hand and verify that +.2 volts (logical low) is present at the top pin of connector W3P5.
4.2.4

Take-Up Reel Motor

Removal
1.

Remove take-up hub assembly (Paragraph 4.1.4).

With tape deck in maintenance position (Paragraph
4.2.1), remove acoustic cover (Paragraph 4.2.2).

Detach connector W4P2 from tach assembly on takeup motor (Figure 4-10).
NOTE

Check

W4P2

position

using

strip

connector.

Detach B3P1 connector from power amplifier module

(connector J1 on power amplifier).

REMOVAL AND REPLACEMENT

Remove four mounting screws that secure motor to

rear of tape deck. Carefully remove motor from
transport.

Replacement

CAUTION
When you install a motor, make sure no loose
wires are between motor mounting plate and
tape deck.

Position motor on rear of tape deck so B3P1 cable
extends from right of motor assembly.

Connect B3P1 cable to power amplifier module.

Connect W4P2 cable to tach assembly on motor.

Replace protective acoustic cover (Paragraph 4.2.2).

Replace take-up reel and hub assembly (Paragraph
4.1.4).

If required, return tape deck to operating position.

Verification Check

With tape not threaded, execute Operator Diagnostic

Test 03.

Thread tape (but do not load) and execute Operator

Diagnostic Test O1.
4.2.5

Air Bearing Sensor

Removal

NOTE
Replacement parts for air bearing assembly are
contained in spares under kit PN 29-24359.
This kit contains two spring guides (one front
and one rear), a sensor, and small and large Orings. If you are replacing sensor Digital recom-

mends that you also replace two spring guides
and large and small O-rings.

CAUTION
Use tape to secure air bearings to tape deck.
1.

Remove magnetic head dust covers.

Tilt tape deck into maintenance positiori (Paragraph
4.2.1).

REMOVAL AND REPLACEMENT

3. Locate supply or take-up air pressure sensors and
their respective connectors on bottom of tape deck.
Detach cable connector (check W1 cable for supply
sensor, and W9 cable for take-up sensor) from sensor
pins (Figure 4-12).
NOTE

Check (and mark if necessary) pins on sensor
and cable plug for proper reconnection.
CAUTION

Make sure not to bend sensor pins when you
detach cable. Pins can easily bend and break.
NOTE

Replace spring guide(s) as necessary.

4. Remove two mounting screws that secure air bearing
assembly to bottom of tape deck. Tear off tape and
remove complete air bearing assembly from top of
tape deck.

CAUTION

Do not remove assembly screws. Make sure
large O-ring does not fall out of air bearing.

PIN 4

LABEL

LARGE “O" RING

INTO AIR BEARING
SMALL “O" RING

INTO SENSOR

SENSOR CABLE
CONNECTOR

SENSOR

MOUNTING
SCREWS

SENSOR

PIN 4
MA-0466-82

Figure 4-12

Air Bearing Sensor Assembly

REMOVAL AND REPLACEMENT

5. Place assembly on flat surface and remove two screws
that secure sensor to rear of air bearing.
CAUTION

Small O-ring is underneath sensor. Do not lose
it.

NOTE

If necessary, you can now remove spring guide.
Replacement

1. Insert small O-ring in aperture at rear of air bearing
housing.

2. Position new sensor on air bearing and secure with
two mounting SCrews.

3. With large O-ring properly seated in aperture on air
bearing, position air bearing assembly onto tape deck
and tape it. Then, use two mounting screws to secure
air bearing to bottom of tape deck.

4. Reattach connector to sensor pins (Figure 4-12).
Verification Check

1. With tape threaded, but not loaded, execute Operator
Diagnostic Tests 02 and 03.

4.2.6

Pneumatic Pump Assembly (Compressor)

Removal

1. Turn off power switch and unplug power cord.

2. With tape deck in maintenance position (Paragraph
4.2.1), remove acoustic cover (Paragraph 4.2.2).
3. On pneumatic pump (Figure 4-13), remove vacuum
and pressure tubes from nipples on bottom of tape
deck behind pump.
NOTE

Mark nipples for proper tube reattachment.

4. Detach B2P1 connector (W4 cable) which connects
pump to power supply connector W4P4.
NOTE

Detach any wiring that may interfere with
removing pneumatic pump assembly.

5. Remove four mounting screws that secure pneumatic
pump assembly to bottom of tape deck. Carefully
withdraw assembly from transport.

REMOVAL AND REPLACEMENT

PNEUMATIC TUBE

\§

TO FILTER BOX

PNEUMATIC TUBE

—,

TO TAPEDECK

[

MOUNTING

SCREWS (4)

PNEUMATIC
PUMP

ASSEMBLY

MA-0032-83

Figure 4-13

Pneumatic Pump Assembly

Replacement

Position new pneumatic pump assembly in place on

tape deck and secure with mounting hardware.
2.

Attach pneumatic tubing to corresponding nipples on

tape deck plenum behind pump.
3.

Attach B2P1 connector (W4 cable) to pump.
NOTE
Reattach

any

wiring

disconnected

during

removal.

Replace acoustic cover (Paragraph 4.2.2).

If required at that time, return tape deck to operating
position. Power on transport.

Verification Check

With tape threaded, but not loaded, execute Operator
Diagnostic Test 02.

With tape threaded, but not loaded, execute Operator

Diagnostic Test O1.

REMOVAL AND REPLACEMENT

4.2.7

Pressure Regulator and Air Filter Assembly

Removal
l.

Tilt tape deck into maintenance position (Paragraph
4.2.1).
NOTE

If you are replacing pressure regulator only,
unscrew (counterclockwise) it from plenum box
assembly, replace with new regulator; then perform verification check.

2. Remove two pressure tubes (Figure 4-14) from plenum box.

NOTE

You cannot mix up these tubes. Make sure they
are marked for easy replacement.

3. Unscrew pressure regulator by turning counterclockwise (Figure 4-14).

Remove plenum box by removing four mounting
SCrews.

NOTE

Make sure screws do not fall into cabinet. Screw
in lower left corner is especially difficult.

Remove air filter by pulling straight out from plenum
box interior.

Replacement

1. Position filter over shaft and press onto filter base.
NOTE

Make sure O-ring is in place on filter base so
that seal is maintained between base and filter
can.

Replace plenum box and secure to tape deck with
four mounting screws.

3. Screw pressure regulator clockwise onto filter shaft.
Install two pressure tubes. Make sure they are on
proper nipples.

REMOVAL AND REPLACEMENT

FILTER
BOX
PRESSURE

REGULATOR

FILTER

MA-0456-82

Figure 4-14

Pressure Regulator/Air Filter Assembly

Verification Check
With tape threaded, but not loaded, execute Operator

Diagnostic Test 02.

With tape threaded, but not loaded, execute Operator
Diagnostic Test 01.

4.2.8

Magnetic Head Assembly

CAUTION
Magnetic head and two write resistors on read/

write/servo module (R224/R225) are matched

components. If you are replacing head, you must

also replace write resistors. Resistors are supplied with new head and labeled with head serial
number, resistor number (R224 or R225), resistor value, and equivalent write current and dc
voltage.

REMOVAL AND REPLACEMENT

Removal

. Remove head dust covers from tape deck.
2. From top of transport, detach read head connector

(Figure 4-15) W6P1, write head connector WS5PI,
and erase head wires P3/P4 from magnetic head.
Move cables out of way.
NOTE

Before you remove head, tape piece of soft, nonsticky material across recording surface. Then,
tape head to tape deck to keep from falling.

WHITE TO FRONT

P3/P4
BLACK TO BACK -

wp1—s

ERASE

WRITE

WGP1——->|:
READ

MAGNETIC HEAD
CONNECTORS

HEAD SCREWSH
ALIGNMENT

(DO NOT
LOOSEN)

MAGNETIC

HEAD ASSY

MOUNTING

SCREWS (4)

MA-0457-82

Figure 4-15

Magnetic Head Assembly

REMOVAL AND REPLACEMENT

Turn off power switch and unplug power cord. Tilt

tape

deck

into

maintenance

position

(Paragraph

4.2.1).
CAUTION
Refer to Figure 4-15 for location of head
mounting screws. Do not loosen factory alignment

screws

head;

otherwise,

you

must

replace entire head with a new assembly. Head

is factory-positioned on base and must never be
moved.

Loosen four head mounting screws. Hold or tape head
against

tape

deck

while

you

remove

mounting

hardware.

Carefully withdraw complete head assembly from
tape deck (Figure 4-15).

Open logic cage and gain access to read/write/servo

module (Paragraph 4.2.12).
Remove write resistors R224 and R225 from read/

write/servo module at location 17F (refer to Figure
A-1). These resistors are plugged in and can be
removed without removing board from logic cage.
NOTE
Keep magnetic head and write resistors together
as package, if head is being returned to factory.

Replacement
1.

Plug new write resistors R224 and R225 into read/
write/servo module, location 17F.

NOTE
Before you install a magnetic head, make sure
recording

surface

protected

with

soft

material.
Insert magnetic head up through tape deck, and posi-

tion head onto guide pins.
.

While you hold head in place, insert mounting hard-

ware and tighten four mounting screws.
.

Guide read and write erase cables through tape deck.

From top of tape deck, attach read, write and erase
connectors to magnetic head (Figure 4-15). Remove
recording surface protective covering.

REMOVAL AND REPLACEMENT

Verification Check

NOTE

To run tests, power on transport and secure tape
deck in operating position.

1. Clean magnetic head recording surface with soft lintfree cloth moistened with tape transport cleaner (supplied). Wipe recording surface in same direction as
tape motion, and at 90° to tape motion.

2. Load known good quality write-enabled scratch tape
and execute Field Service Diagnostic Test 18 to move
tape away from BOT. Press RESET to stop tape after
about five seconds.
NOTE

For next step, set tape deck into service position.

3. Move jumper plug at location 13E on read/write/
servo module from normal W3 to test 31 W4-STORE
position (refer to Figure A-1).

4. Execute Field Service Test 31.

5. After test is successful (display 00), return jumper
plug to normal W3 position. Close logic cage. Return
tape deck to operating position.

If test is not successful, proceed with fault isolation
and required actions described in TU80 Pathfinder.
6. With tape still threaded, but not loaded, execute
Operator Diagnostic Test O1.

4.2.9

Cooling Fan Assembly

Removal

1. Tilt tape deck in maintenance position (Paragraph
4.2.1).

2. Detach W4P5 connector from power supply.
3. Remove four hex nuts and washers and pull fan
assembly from mounting studs (Figure 4-8).
Replacement

Perform Removal procedure in reverse.
Verification Check

Turn on power to transport and check for air flow from
fan.

REMOVAL AND REPLACEMENT

4.2.10

Control Panel Assembly

Turn off power switch and unplug power cord.

Open front door. Find ground strap and remove screw
that secures strap to tape deck (point E2). Remove
hex nut that secures strap to rear of door (Figure
4-16).
Tilt tape deck in maintenance position (Paragraph
4.2.1).

On formatter/control module (refer to Figure A-2)
detach control panel cable connector W8P1 from P7

Remove cable from clips on front door and cabinet.

plug.

(Cut straps if necessary.)
.

From front of transport, remove four hex screws that
hold control panel to front door. Remove control
panel assembly and cable.

CONTROL
PANEL

MODULE

INSIDE

COVER

SIGNAL
CABLE
MA-0035-83

Figure 4-16

Control Panel Assembly

REMOVAL AND REPLACEMENT

Replacement

Insert ground strap, W8 cable, and control panel
through front door opening. Then secure panel to

door with four mounting screws.

Attach and secure ground strap and ground wire on
front door and tape deck. Connect W8P1 cable connector to P7 plug on formatter/control module. Use
cable clips on back of front door to secure loose cable.
Power on transport.

Verification Check
1.

Perform functional troubleshooting procedures 1001

through 1003.
2.

With tape threaded, but not loaded, execute Operator
Diagnostic Test O1.

4.2.11

Power Supply

Removal
1.

Open front and rear doors. Remove frame stabilizing
bar if high enough to be in the way (Figure 4-17).
Turn off power switch. Unplug 874 controller power
cord. Tilt tape deck to maintenance position
(Paragraph 4.2.1).

. Disconnect power cable from 874 power controller
and put cable aside).

Detach W4P4, W2P1, W7P1, and W4P5 connectors
from power supply.

NOTE

Power supply weighs approximately 4.1 kg (9
Ibs). Proceed with caution when you lift it.

Return tape deck to operating position. From rear of
unit, remove stabilizing plate mounting screw (Figure
4-17).
NOTE

Power supply is attached to tape deck by four
screws. Two screws on left are located in slots
so you can slide power supply out from under
these screws for removal.
Loosen but do not remove two mounting SCrews on

left side of power supply.

REMOVAL AND REPLACEMENT

LOOSEN BUT
DO NOT

REMOVE

2 SCREWS

FROM SLOTS///

REMOVE

2 SCREWS

{ | STABILIZING

POWER

SUPPLY

PLATE

\COOLING
FAN

TUB0

REAR CABINET
MA-0078-83

Figure 4-17

Power Supply Removal

Remove two mounting screws on right side of power
supply while you support power supply from bottom.
Slide power supply out of slots on left and carefully
remove power supply from cabinet.

Replacement

If your replacement power supply is PN 29-26372, you
must complete the following procedure first.

Remove the voltage select access panel from new power supply and verify that the voltage select plug is
inserted in the correct voltage receptacle. J11 is for
120 volt operation and J12 for 220-240 volt operation.

Secure the voltage select access panel.

Check the position of the AUTO POWER ON

switch. For use in a TUS8O, the switch should be set in

the ‘OFF’ position.

REMOVAL AND REPLACEMENT

CAUTION

If you are installing new power supply, remove

top cover from power supply enclosure and
observe position of voltage select card (Figure
4-18). Position of card must correspond to input
voltage as defined on transport’s identification
plate. Ends of card are stenciled with “120 V”
and “220 V” and two indicating arrows. Make
sure card is installed to match input voltage.
You can lift card, turn it upside down, and
replace it onto the main power supply module as
required. Arrows for correct positioning are
marked on module.

1. Remove top cover of power supply.

. Make sure voltage select module (Figure 4-18) is
installed in correct position. Then replace cover.

. From rear of transport, slide power supply under two
installed mounting screws.

. Insert and tighten other two mounting screws. Then
tighten two mounting screws on left.
. Install stabilizing plate, and insert and tighten mountIng sCrew.

120V

220V

203

JAE

2A
250V

1/16A

1/8A

250V

] 20

1 (2418
120V

220V
MA-0455-82

Figure 4-18

Voltage Select Card

REMOVAL AND REPLACEMENT

Turn tape deck to maintenance position.

Attach W4P4, W2P1, W7P1, and W4P5 connectors
to power supply plugs.

8. Connect power cable to TU80 power supply and plug
874 controller power cord into power outlet.
Verification Check

NOTE

Power Supply is provided as completely assembled FRU and does not require verification
check. However, if power problem occurs, you
may check dc voltages.
DC Voltage Checks — Use a digital voltmeter to measure
all dc voltages. Connect meter’s ground lead to either pin 4

or 6 of the W7P1 power connector on read/write/servo
module (Figure 4-19). Connect other meter lead to points
listed below to test all dc voltages.

READ/WRITE/SERVO
MODULE

W7P1

RED

7 (+24)

BLK

6 (GND)

RED

(+5)

‘

BLK

(GND)

¢__BLUMWHT |

{ _ RED/WHT

]

—
T
flfij

[:[m [

21 (NC)*
(-15) ;D
:l Dm D,
3 (+15)

* NO CONNECTION

]

it gl LI [

® e |0

MA-0460-82

Figure 4-19

DC Voltage Checks

REMOVAL AND REPLACEMENT

DC Voltages and Tolerances

Location Voltage
+5V
P1-5%

—15V
+15V
+24'V
—6V
+38V

P1-2*%
P1-3*
P1-7*
P1-8*
J4-61

Tolerance
(+4.90 to +5.10)
+2%

*10%
+10%
+10%
+10%
+10%

(—13.5t0—16.5)
(+13.5t0 +16.5)
(+21.6t0+26.4)
(—5.4t0—6.6)
(+34.2to +41.8)

Read/Write/Servo Module

4.2.12
Removal
l.

Turn off power switch.

Tilt tape deck into maintenance position (Paragraph
4.2.1).

Detach all cable connectors from read/write/servo

board connectors (Figure A-1).

To release read/write/servo module, loosen thumbscrews on logic cage (Figure 4-20) as follows.
a. To open

logic cage,

loosen

top and bottom

thumbscrews.

b. To separate modules, loosen middle thumbscrews.
NOTES

1. Avoid undue stress on modules by loosening
thumbscrews alternately until modules are
separated.

2. There are two screws in each hinge of logic
cage. The screws are never removed. They
are loosened only enough to clear module
they hold.

Loosen and back out top screws on each hinge of logic
cage (three) to release read/write/servo module
(Figure 4-20).

Pull read/write/servo module from P1 connector and

remove module from logic cage.

* P1 is power connector on read/write/servo module.
T J4 is power connector on power amplifier module.

REMOVAL AND REPLACEMENT

1. TOP SCREW (TOP & BOTTOM HINGES)
BACK OUT TO REMOVE READ/WRITE/
SERVO MODULE.

2. BOTTOM SCREW (TOP & BOTTOM HINGES)

BACK OUT TO REMOVE FORMATTER/
CONTROL MODULE.

LOGIC CAGE

LOOSEN THUMB SCREWS

(TOP AND BOTTOM)
SEPARATE
MODULES

READ/WRITE
SERVO

MODULE

FORMATTERL\\\\\\\\H
CONTROL
MODULE

/O CABLE

CONNECTORS
TO P4 & PS5

LOOSEN THUMB SCREWS
(TOP AND BOTTOM)
TO SWING MODULES OPEN

Figure 4-20

Logic Modules in Logic Cage

MA-0462-82

REMOVAL AND REPLACEMENT

Replacement

NOTE
If you are installing a new logic module, remove

R224 and R225 write resistors from removed
module and insert these resistors into new
module.

. Install new read/write/servo module in its place in
logic cage. Make sure module is fully inserted into top
and bottom hinge slots.

Pull in and tighten hinge screws to lock read/write/

servo module in position.

. Attach cable plugs P2 and P3 from formatter/control
module to J2 and J3 connectors on read/write/servo
module (Figure A-1).

Attach remaining cable connectors to module plugs
as listed below.

J1
J4
J5
J6
J7

WS5P2 connector (write/erase heads)
W1 cable (supply reel tension sensor)
W3P8 connector (BOT/EOT sensors,
cover interlock, power amplifier, tachs)
W6P2 connector (read head)
W9 cable (take-up reel tension sensor)

Push two modules together and tighten thumbscrews
to secure read/write/servo module in logic cage.
Verification Checks
I

With tape threaded, but not loaded, execute Operator
Diagnostic Test 02.

Move jumper plug at location 13E on read/write/
servo module from normal W3 to test W4-STORE
position.

With tape not threaded, execute Field Service Test
37.

Load known good quality write-enabled tape.
5. Execute Field Service Test 18 to move tape away

from BOT. Press RESET to stop tape motion after

about five seconds.

Execute Field Service Test 31.

r—

AT A

REMOVAL AND REPLACEMENT

After test is complete (display 00), return jumper
plug to W3 position. Otherwise, proceed with fault

With tape threaded, but not loaded, execute Operator

1solation and required actions.
Diagnostic Test 0O1.
4.2.13

Formatter/Control Module

Turn off power switch.

Tilt tape deck to maintenance position (Paragraph
4.2.1).

Remove two screws from each I/O cable plug secured
in logic cage mounting bracket. Then detach two

external interface shielded cables (Figures 4-7 and

4-20).

NOTE
Tighten the screws to leave two ribbon I/0
cables in slots inserted in logic cage mounting

bracket.
4.
5.

Detach all remaining cable connectors (Figure A-2)
from board connectors.
To release formatter/control module from logic cage

(Figure 4-20) loosen thumbscrews on each side of
cage.

a. To opén logic rack, loosen top and bottom
thumbscrews.

To separate modules, loosen middle thumbscrews.

NOTE
Avoid undue stress on modules by loosening
thumbscrews alternately until modules are
separated.

Loosen and back out (but do not remove) bottom
screws on each hinge (three) to release formatter/

control module.

Pull formatter/control module from Pl
and remove module from logic cage.

connector

REMOVAL AND REPLACEMENT

Replacement

NOTE

Before you install formatter/control module, set
all jumpers and switches to position they were
set at in removed module (Figure 2-1). Set all
switches (S1-S4) of four-segment DIP switch at
location D21 to off. Also make sure jumpers
(W5) at location E16 are in NORMAL position.

1. Install formatter/control module in top and bottom
hinge slots of logic cage. Make sure module is fully
inserted.

2. Pull in and tighten hinge screws (three) to lock
formatter/control module in position.
3. Attach [/O ribbon cables to P5 and P4 connectors on
module. Refer to Figure 2-5 for correct 1/O cable
interconnections.

4. Push two modules together. Then align and tighten
thumbscrews.

5. Attach cable connectors to module plugs as listed
below.

W7 cable (power amplifier module and

power supply)
P2 and P3 Cables from J2 and J3 connectors on
read/write/servo module

P4 and P5 Flat I/O cables to bulkhead bracket
connectors

P6
P7

W2P1 cable connector (power supply)
W8P1 cable connector (control panel)

Verification Check

1. With tape threaded, but not loaded, execute Operator
Diagnostic Test O1.

NOTE

After you successfully complete module replacement and checking, reattach and secure two
external interface cables on mounting plate
bracket of logic cage. Return tape deck to operating (horizontal) position.

REMOVAL AND REPLACEMENT

4.2.14

Power Amplifier Module

Removal

1. Turn off power switch. Unplug power cord.
2. With tape deck in maintenance position (Paragraph
4.2.1), remove acoustic cover (Paragraph 4.2.2).
3.

Detach cable connectors J1 through J4 from module
(Figure A-3).

Remove three screws along outside edge of module to
release it from mounting rack (Figure 4-8). Remove
module.

Replacement

Insert new module into slots in mounting rack. Make
sure module 1s in place.

2. Replace and tighten three screws to secure module in
rack.

Reattach cable connectors as follows.

B3P1 cable connector (take-up reel motor)
W3P7 cable connector (read/write/servo

J1
J2
|

J3
J4

module)

BI1P1 cable connector (supply reel motor)
W7P2 cable connector (power supply)

Verification Check

Individually execute Operator Diagnostic Tests 03 (tape
not threaded), 02 (tape threaded, but not loaded), and 01
(tape threaded, but not loaded).
NOTE

After you successfully complete module replacement and checking, replace protective acoustic
cover and return tape deck to operating (horizontal) position.

REMOVAL AND REPLACEMENT

4.2.15

Top Cover Interlock Switch

Removal
1.

With tape deck in maintenance position (Figure
4-21), remove four labeled slip-on connectors from
interlock switch connectors. (If any wires are not
labeled, identify and mark each wire for proper
reattachment.)

Remove two mounting screws that secure switch plate
to tape deck. Remove switch and switch plate.
Press top and bottom release tabs on switch to sepa-

rate switch from switch plate.
Replacement
l.

Assemble switch to switch plate.

Position switch assembly on rear of tape deck so connector numbers on switch correspond to numbers on
tape deck.

Insert two hex mounting screws. Position top cover
door so interlock switch can be aligned with actuating
stud on door. Tighten switch mounting screws when
center of switch front is aligned with actuating stud.

Attach slip-on connectors to appropriate studs of
interlock switch (Figure 4-21).
Verification Check

With tape threaded, but not loaded, execute Operator
Diagnostic Test O1.

4.2.16

Capacitor Assembly

Removal
1.

Tilt protective tape deck to maintenance position and
remove acoustic cover.

Detach capacitor connector from J5 on power amplifier module.
NOTE

Do not remove protective terminal caps on top
of capacitor during removal or replacement
procedures.

Remove three screws from capacitor
assembly. Remove capacitor assembly.

mounting

REMOVAL AND REPLACEMENT

TM
;
P9-31—s
P10-32

~ar”

P4-12

—

P3-11
0

L
Figure 4-21

MA-0077-83

Door Interlock Switch (Maintenance View)

Replacement
I.

Mount replacement capacitor assembly as shown in
Figure 4-22 and install three screws. Tighten securely.

Install capacitor connector to J5 on power amplifier

module.
Verification Check
Thread tape (not loaded) and run Operator Diagnostic
Tests 01 and 02.

REMOVAL AND REPLACEMENT

CAPACITOR

ASSEMBLY
~—

POWER
AMP

MODULE

MA-0117-83

Figure 4-22

Capacitor Assembly

MODULE LAYOUTS

READ_
HEAD

F/C

MODULE

TAKE-UP
R

WRITE AND 1
ERASE
HEADS

POWER

BOT/EOT,
FILE PROTECT,
TACHS, DOOR
INTERLOCK,
POWER AMP

Figure A-1

| _F/C

MODULE

SUPPLY AIR
BEARING
SENSOR

SUPPLY

Read/Write/Servo
Module Layout

MA-0430A-82

APPENDICES

R/W/S

T ——*
MODULE

CONTROL

PANEL

m
P5

M7454

UNIBUS

ADAPTER

|, POWER
P6

SUPPLY

]

POWER

la—

SUPPLY

RIW/S

— q—>s

MODULE

MA-0414-82

Figurc A-2

Formatter/Control Module

APPENDICES

SUPPLY
MOTOR

MODULE

POWER

SUPPLY
TAKE-UP

o
MA-0435A-82

Figure A-3

Power Amplifier Module

B TU80 REGISTERS

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L1SX

£1SX

APPENDICES

BUS ADDRESS REGISTER (TSBA)

— TSBA
— (READ ONLY)
BUS ADDRESS

UNIBUS ADDRESS+0

15114

12|11

09)08

06|05

03}02

A15| a14|A13] A12] A11] A10| A09| AD8 | AD7 | ADE| ADS | AD4| AO3|AD2| AOT|AOO
sis|sls|s|s|s|s|s|s|s|s]|]s]|s}|s
sl
DEFINITION

NAME

BIT
15
14
13
12
11
10
09
08
07
06
05
04
03
02
01
00

A15
A14
A13
A12
A11
A10
A09
A08
AQ7
A0B
A05
AO4
AO3
A02
AO1
A00

BUS ADDRESS BIT 15
BUS ADDRESS BIT 14
BUS ADDRESS BIT 13
BUS ADDRESS BIT 12
BUS ADDRESS BIT 11
BUS ADDRESS BIT 10
BUS ADDRESS BIT 09
BUS ADDRESS BIT 08
BUS ADDRESS BIT 07
BUS ADDRESS BIT 06
BUS ADDRESS BIT 05
BUS ADDRESS BIT 04
BUS ADDRESS BIT 03
BUS ADDRESS BIT 02
BUS ADDRESS BIT 01
BUS ADDRESS BIT 00

100000
40000
20000
10000
4000
2000
1000
400
200
100
40
20
10
4
2
1

MA-4008

Bus Address Register

Figure B-2

DATA BUFFER REGISTER (TSDB)
UNIBUS ADDRESS + 0 — DATA BUFFER — (WRITE ONLY) — TSDB

|14

12|11

p15|P14|P13|P12|

BIT

NAME

15
14
13
12
11
10
09
08
07
06
05
04
03
02
01
00

P15
P14
P13
P12
P11
P10
P09
P08
PO7
P06
P05
P04
P03
P02
P17
P16

Figure B-3

o09]

06|05

03]02 01

P11|P10| P09 | PO8|PO7 | POG | POS | PO4 | PO3|PO2|P17 | P16

DEFINITION

100000
40000
20000
10000
4000
2000
1000
400
200
100
40
20
10
4
2
1

COMMAND POINTER BIT 15
COMMAND POINTER BIT 14
COMMAND POINTER BIT 13
COMMAND POINTER BIT 12
COMMAND POINTER BIT 11
COMMAND POINTER BIT 10
COMMAND POINTER BIT 09
COMMAND POINTER BIT 08
COMMAND POINTER BIT 07
COMMAND POINTER BIT 06
COMMAND POINTER BIT 05
COMMAND POINTER BIT 04
COMMAND POINTER BIT 03
COMMAND POINTER BIT 02
COMMAND POINTER BIT 17
COMMAND POINTER BIT 16

Data Buffer Register

M A-4009

APPENDICES

STATUS REGISTER (TSSR)
(UNIBUS ADDRESS + 2 — READ ONLY)
15114

12|11

SC
S

09}08

06|05

s|{as|s

100000

s]|

s|s

RMR

10000

NXM

4000

NON-EXISTENT MEMORY

2000

NEED BUFFER ADDRESS

A17

1000

UNIBUS ADDRESS BIT 17

400

UNIBUS ADDRESS BIT 16

SSR

200

SUBSYSTEM READY

100

OFF-LINE

TERMINATION CLASS BIT 02

TC1

TERMINATION CLASS BIT 01

TCO

TERMINATION CLASS BIT 00

Figure B-4

MA-40124

Status Register

RESIDUAL FRAME COUNT REGISTER
RBPCR

.
-

02
C15

c2|Ct1|cCO

BIT

NAME

C15

s|s|s

20
TC2

1000000

THIS WORD WILL CONTAIN THE OCTAL

COUNT OF RESIDUAL BYTES/RECORDS/

TAPE MARKS FOR THE READ, SPACE

RECORDS, AND SKIP TAPE MARK

COMMANDS. THE CONTENTS ARE
MEANINGLESS FOR ALL OTHER

COMMANDS.

MA-5349

Figure B-5

A16
OFL

03|02

TC2| TC1|TCO

SPECIAL CONDITION

40000

20000

NBA

RMR|NXM|NEA| A17| A16| SSR OSFL

Residual Byte Count Register

APPENDICES

EXTENDED STATUS REGISTER O (XSTAT 0)

15114

12|11

o09]o8

06|05

mrlrLs |LET [RLLiwLE|NEF| iLC | 1LA|MOT]|ONL]
s2l

212121363

TMK

RLS
LET
RLL
WLE
NEF
ILC
ILA
MOT
ONL

|3]|3 ]| s

[s13

03|02

|s3]|Ss

TAPE MARK (READ-SPACE/WRITE-SKIP/OTHER

100

ON-LINE

VCK
PED
WLK

20
10
4

BOT
EOT

2
1

IE |vCK|PED|WLK|BOT|EOT

100000

[s36523]S2

RECORD LENGTH SHORT
LOGICAL END OF TAPE
RECORD LENGTH LONG
WRITE LOCK ERROR
NON-EXECUTABLE FUNCTION
ILLEGAL COMMAND |
ILLEGAL ADDRESS
CAPSTAN MOVING

40000
20000
10000
4000
2000
1000
400
200

INTERRUPT ENABLE

VOLUME CHECK
PE DRIVE
WRITE LOCK

BEGINNING OF TAPE
END OF TAPE

Figure B-6

Atotin

Extended Status Register 0

EXTENDED STATUS REGISTER 1 (XSTAT 1)

15|14

DLT

COR

12]

DLT

100000

|os

RPE

S,4

40000

20000

CORRECTABLE DATA

NA
NA
NA
NA

4000
2000
1000

10000

NA
NA
NA
NA

RPE

400

READ BUS PARITY ERROR

200

100

IPO

INVALID POSTAMBLE
NA

UNC

UNCORRECTABLE DATA *
MULTITRACK ERROR

03|02

sS4

UNCIMTE

4 | 4

DATA LATE ERROR

COR

MTE

|05 04

IPO

*UNCORRECTABLE DATAWILL BE FLAGGED ON A WRITE ERROR.
MA-4010A
SHR-0346-87

Figure B-7 Extended Status Régister 1

APPENDICES

EXTENDED STATUS REGISTER 2 (XSTAT2)
15114

OPM

|WCF

DTP|DT7|DT6|DTS|DT4

80 | 5

| 05

s{s|s|s|s

OPM

100000

OPERATION IN PROGRESS (TAPE MOVING)

-----

40000

20000

10000

TUSO

4000

TU8SO

WCF

2000

WRITE CLOCK FAILURE

—

1000

DTP

400

DEAD TRACK INDICATORS FOR TRACKS

DT7

200

DT6

100

DT5

DT4

DT3

DT2

DTO

DT1T 2

DEAD TRACK INDICATORS FOR TRACKS

Extended Status Register 2

Figure B-8

EXTENDED STATUS REGISTER 3 (XSTAT3)
J

12 l11

09 108

7 l 7

100000

TRANSPORT ERROR COD

06 | 05

OPI |IREV

40000

20000

10000

4000

2000

1000

400

200

OPI

100

OPERATION INCOMPLETE

REV

TAPE MOTION REVERSE: [F MULTIPLE RETRY AT

LEAST 1 WAS REVERSE
DCK

RiB

DENSITY CHECK

REVERSE INTO BOT

Figure B-9

Extended Status Register 3

%?-

15 l 14

OBSERVE ANY

ERRORS, FAULTS,

4‘

HALTS IN TU80

THREAD TAPE

SUBSYSTEM

INITIATE OPERATOR
TEST 01

TURN TAPE

TRANSPORT
POWER OFF

)

DOES

CHECK HOST

TU8O

SYSTEM

POWER ON AND

OPERATE

PRESS LOGIC ON

O'K

ERROR LOG

TO RUN TU80
POWER-ON HEALTH

CHECK

PLACE TU80

USE PATHFINDER

ON-LINE. RUN

TO TROUBLESHOOT

TU80 HOST

FAULT CODE

DIAGNOSTICS

!
REPLACE OR

COMPLETE

REPAIR FAILED

DIAGNOSTIC

FRU

FAILS

INITIATE
M7454

POWER

POWER-ON

INDICATOR

SELF-TEST

DOES

TU8O

USE PATHFINDER
PROCEDURES

OPERATE

1001 - 1003 TO

TRACE FAULT

,_{

REPLACE

FAILED FRU

POWER-UP

CONTINUE WITH

FAULT CODE

HOST CHECK
CHECK & REPLACE

REPLACE

AND SYSTEM

/O CABLES

M7454

DIAGNOSTIC

USE PATHFINDER

TO TROUBLESHOOT

CHECK AND

FAULT CODE

REPLACE TUS80

FORMATTER

REPLACE OR

REPAIR FAILED
FRU

CHECK
& REPL_ACE

M7454
MA.0083-83

Troubleshooting Flowchart