DECstation 5000 System 5000 Model 200 Maintenance Guide

This "DECstation 5000/DECsystem 5000 Model 200 Maintenance Guide," published in 1990, is intended for trained Digital customer service representatives. It provides comprehensive instructions for the maintenance, troubleshooting, and replacement of Field Replaceable Units (FRUs) for these ULTRIX-based RISC desktop systems.

The guide covers:

• Hardware Overview: Details the system unit's basic and optional hardware configurations, including its CPU, FPU, SCSI and ThinWire Ethernet controllers, memory and TURBOchannel expansion slots, and various external connectors and indicators. It also describes supported peripherals like drives, monitors, keyboards (LK201), and mice (VSXXX-AA).
• Service Operations: Provides practical procedures for routine maintenance, such as preventing electrostatic damage, using an alternate terminal, and the removal and installation of system covers, front plates, serial number plates, and different types of loopback connectors and terminators. It also explains how to enter console and operating modes, manage console command passwords, and boot or shut down system software.
• Troubleshooting Tools: Explains how to utilize various tests (power-up self-tests, individual subtests, test scripts) and interpret their results from monitor displays or diagnostic LEDs. A significant portion details how to examine and interpret ULTRIX error logs (memory, error and status register, and overheat logs) to identify and locate failures.
• Identifying Failed FRUs: Offers a structured troubleshooting process, including steps for addressing power issues, interpreting diagnostic error messages (both on the monitor and via LED codes), and using error logs to pinpoint intermittent failures or problems with peripherals.
• Basic Hardware Maintenance: Provides detailed troubleshooting steps and removal/installation instructions for core components like the system module and chassis (emphasizing they are an inseparable unit), memory modules, the keyboard and mouse, and the power supply (including fan troubleshooting).

Appendices offer essential reference information, including equipment specifications (physical dimensions, operating conditions), a recommended spares list with part numbers, and extensive lists of console commands and test commands with their corresponding error messages and codes. The guide notes that some command and error information varies based on the system's ROM chip version (e.g., PDE3 ROM chips), and refers to a separate "TURBOchannel Maintenance Guide" for details on TURBOchannel options, drives, and monitors.