IBM 8669 - Eserver xSeries 342, Hardware Maintenance Manual

Page: 21 / 156

Diagnostics
This section provides basic troubleshooting information to help you resolve some
common problems that might occur with the server.
Diagnostic tools overview
The following tools are available to help you identify and resolve hardware-related
problems:
v POST beep codes, error messages, and error logs
The power-on self-test (POST) generates beep codes and messages to indicate
successful test completion or the detection of a problem. See “POST” on page 12
for more information.
v Diagnostic programs and error messages
The server diagnostic programs are stored in upgradable read-only memory
(ROM) on the system board. These programs are the primary method of testing
the major components of the server. See “Diagnostic programs and error
messages” on page 13 for more information.
v Light path diagnostics
The server has light-emitting diodes (LEDs) to help you identify problems with
server components. These LEDs are part of the light-path diagnostics that are
built into the server. By following the
path of lights , you can quickly identify the
type of system error that occurred. See “Light path diagnostics” for more
information.
Identifying problems using LEDs
The server has LEDs to help you identify problems with some server components.
These LEDs are part of the light path diagnostics built into the server. By following
the
path of lights , you can identify the type of system error that occurred. See the
following sections for more information.
Power supply LEDs
The AC and DC Power LEDs on the power supply provide status information about
the power supply. See “Power supply LED errors” on page 92.
Light path diagnostics
You can use the light path diagnostics built into the server to quickly identify the
type of system error that occurred. The diagnostics panel is under the air baffle.
The server is designed so that any LEDs that are illuminated remain illuminated
when the server shuts down as long as the AC power source is good and the
power supplies can 5V DC current to the server. This feature helps you
isolate the problem if an error causes the server to shut down. See “Light path
diagnostics” on page 12.
Diagnostics panel
The following illustration shows the LEDs on the diagnostics panel on the system
board. See “Light path diagnostics” on page 12 for information on identifying
© Copyright IBM Corp. 2000, 2001
11