Testing and Troubleshooting
Chapter
3
Introduction
This chapter contains information to help you test the computer
and
diagnose failures. T rouble-
shooting
and
repair strategy
is
briefly described. Then, the problem isolation section relates service
panel indications to probable faults.
The remainder of the chapter contains descriptions of the service processor code, loader
ROM test
module, loader error messages, self-tests
and
diagnostics,
and
early warninglfault tolerance fea-
tures.
Troubleshooting and Repair Strategy
To troubleshoot a failing computer, perform the problem isolation procedures provided below. The
diagnostics
and
service panel indicators are designed to enable fast fault isolation to a replaceable
module. Every replaceable module can
be
replaced within 15 minutes from
fully
assembled
machine, through disassembly
and
replacement, back to
fully
assembled machine.
Chapter 4 contains the procedures to access
and
replace failed modules
in
the computer,
and
Chapter 5 has exploded view drawings of the computer showing attaching parts.
All
replaceable
parts are listed
in
Chapter
5.
Problem Isolation
Figure 3-1 shows the service panel indications of a normal, fault-free power-up sequence from
power
on
to operating system running. A computer fault aborts this sequence.
In
most cases, the
service panel indicates the fault.
3-1