Chapter 4 Fault Isolation - HP 400 Series Servicing Manual

This chapter provides information about isolating a failing Field Replaceable Unit
(FRU). It consists of the following three parts:
• Part 1 contains troubleshooting flowcharts and diagnostic information for sys-
tems that use Domain Compatible mode.
• Part 2 contains troubleshooting flowcharts and diagnostic information for sys-
tems that use HP-UX Compatible mode.
• Part 3 explains checkout procedures for Series 400 systems, which are refer-
enced by the troubleshooting flowcharts.
The flowcharts contained in this chapter are logically structured to point you in the
right direction (run diagnostics, replace FRUs, and so on). The remainder of the infor-
mation in this chapter supports the directions in the flowcharts. Follow the removal and
replacement procedures in Chapter 5 if the flowcharts call for FRU replacements.
Troubleshooting in Domain Compatible Mode
You must be familiar with the Domain/OS shells and commands to troubleshoot Series
400 system units that are running in Domain Compatible mode. You must be able to
start and stop processes. You should also become familiar with a number of standalone
utilities, and with both the online and offline diagnostics. The Domain Hardware Utili-
ties Reference manual describes all standalone utilities for Domain nodes, and Using
Domain Diagnostics, Volume 1 describes the MD environment and the diagnostics.
For Series 400 systems that run Domain Compatible mode, you note any error or status
messages, and then run the power-up diagnostics, known as Self Test. If the Self Test
diagnostics fail, replace the FRU that is indicated. If the tests pass but you still suspect
a problem, you should run the next level of diagnostics. If you can boot Domain/OS,
run the System Acceptance Exerciser (SAX). If you are restricted to the MD, run the
Chapter 4
Fault Isolation
Fault Isolation 4-1