AlphaServer DS20 Service Manual

This document is the Compaq AlphaServer DS20 Service Manual, primarily intended for customer service engineers. It provides comprehensive information for servicing, troubleshooting, configuring, and replacing field-replaceable units (FRUs) of the AlphaServer DS20 system.

The manual is structured into four main chapters and three appendices:

• Chapter 1: System Overview details the system's architecture, components (CPUs, memory, I/O, storage), various internal buses (TIG, I2C, PCI/ISA), and key modules like the Server Feature Module.
• Chapter 2: Troubleshooting guides users through power-up issues, interpreting control panel displays and LEDs, and utilizing diagnostic tools such as the SRM console's test command and Compaq Analyze for error analysis.
• Chapter 3: Error Registers describes the various system registers that store error information related to machine checks and system events.
• Chapter 4: Removal and Replacement provides step-by-step instructions for replacing all major FRUs, including CPUs, memory modules, the system board, PCI/ISA options, power supplies, fans, and storage components, emphasizing safety procedures.

The appendices offer additional critical information:

• Appendix A summarizes SRM console commands, halt button functions, and environment variables for system configuration.
• Appendix B covers remote system management using the Remote Console Manager (RCM) commands and switchpack.
• Appendix C provides instructions for updating system firmware using the Loadable Firmware Update (LFU) utility via CD-ROM, floppy, or network.