Light Path Diagnostics - IBM System x3550 M5 Type 5463 Installation And Service Manual

v Troubleshooting by symptom

Light path diagnostics

Light path diagnostics is a system of LEDs on various external and internal
components of the server that leads you to the failed component. When an error
occurs, LEDs are lit on the operator information panel on the front of the of the
server, then on the failed component. By viewing the LEDs in a particular order,
you can often identify the source of the error.
When LEDs are lit to indicate an error, they remain lit when the server is turned
off, provided that the server is still connected to power and the power supply is
operating correctly.
Before you work inside the server to view light path diagnostics LEDs, read the
safety information "Safety" on page vii and "Handling static-sensitive devices" on
page 124.
If an error occurs, proceed as follows:
1. Look at the operator information panel (see "Operator information panel" on
2. Remove the server cover and look inside the server for lit LEDs. Certain
The following illustration shows the LEDs on the system board.
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IBM System x3550 M5 Type 5463: Installation and Service Guide
10. Intel GPU
11. Nvidia GPU
See "Running the DSA Preboot diagnostic programs" on page 78 for more
information on running the DSA Preboot program on the server.
These tables list problem symptoms and actions to correct the problems. See
"Troubleshooting by symptom" on page 80 for more information.
page 20) on the front of the server.
v If the check log LED is lit, it indicates that information about an un-isolated
fault condition in the server is available in the IMM event log or in the
system-event log.
v If the system-error LED is lit, it indicates that an error has occurred.
components inside the server have LEDs that are lit to indicate the location of a
problem.
The system service label inside the server cover provides an overview of
internal components that correspond to errors indicated by the operator
information panel or LCD operating panel assembly (see "Operator information
panel" on page 20 or "LCD operating panel assembly" on page 21. This
information can often provide enough information to diagnose the error.
Note: You do not have to remove the server cover to view the LEDs on hard
disk drives and power supplies.