RV20 Optical Disk Subsystem Service Guide

This document is the "RV20 Optical Disk Subsystem Service Guide," published by Digital Equipment Corporation in February 1988. It provides comprehensive instructions for the diagnosis, testing, troubleshooting, and physical maintenance (removal and replacement) of the RV20 optical disk drive and its subsystem.

Key aspects covered include:

1. Product and Subsystem Description: Details the RV20 as a Write-Once Read-Many (WORM) random-access mass storage device capable of storing up to one gigabyte per disk side, utilizing a laser system. It describes the subsystem configuration, including its housing in an H9643 cabinet and use of the ISI and LESI buses for communication with a host system (VAX or MicroVAX).
2. Field Replaceable Units (FRUs): Lists all components identified as field-replaceable parts for service.
3. Drive Operation: Explains the controls and indicators on the drive's front, maintenance, and rear panels.
4. Diagnostics and Testing: Provides detailed procedures for running various diagnostics:
   • Host-based Diagnostics: Instructions for running Level III, Level IIR Data Reliability, and Level 2R DUP tests through VAX Diagnostic Supervisor (VDS) and MicroVAX Diagnostic Monitor (MDM). These tests help isolate problems to the RV20 drive or its communication path.
   • Off-Line Testing: Focuses on the "Structured Analysis Method" (SAM) to detect, isolate, and correct RV20 drive problems when disconnected from the host. This includes power-up procedures, automatic self-tests, and Customer Engineer (CE) mode tests.
   • Error Reporting: Explains how to interpret diagnostic error reports, including message fields, error classes, error codes, and subfailure codes, which guide corrective actions. Dedicated diagnostic test disks are required for many tests.
5. Removal and Replacement: Offers step-by-step procedures for disassembling and reassembling all major components of the RV20 drive, categorized into external parts (e.g., covers, panels, filters) and internal parts (e.g., power supply, circuit boards (PCAs), card rack, spindle, carriage assembly, various sensors, and solenoids). Safety precautions such as static discharge control and warnings regarding hazardous voltages and laser optics are emphasized.

The guide is intended for service personnel and assumes the use of specific diagnostic tools and test media.