DECstation 200

This document set comprises two distinct, but related, service manuals for Digital Equipment Corporation's DECstation computers.

The primary document, titled "DECstation 200 Service Guide," is a comprehensive manual designed for service technicians to diagnose and repair the DECstation 200 system. It provides a detailed overview of the system's components and configurations, including its main logic board, bus adapter, memory, power supply, monitors, and various storage devices. The guide offers extensive troubleshooting instructions, covering normal power-up sequences, diagnostic tools, and procedures for various issues like "no power" or "no boot/no video." It also includes procedures for connecting to Ethernet networks (ThinWire and Standard Ethernet), step-by-step instructions for adjusting monochrome and color monitors, and detailed procedures for the removal and replacement of Field Replaceable Units (FRUs) such as the keyboard, monitor, mouse, memory, disk drives, power supply, and main logic board. Appendices cover jumper and switch settings, and interrupt requests.

The second document, "DECstation 220 Maintenance Advisory," acts as a supplement to the DECstation 200/220 service manuals. Its purpose is to document the physical, technical, and functional differences between the DECstation 200 and the upgraded DECstation 220 models. It details upgrades like clock speed, memory access time, and processor changes, outlines service procedure modifications specific to the DECstation 220, and provides relevant part numbers and FRU lists for the 220 model. This advisory is intended to be used in conjunction with the more general service guides for the DECstation 200/220 series to provide complete maintenance information for the DECstation 220.