Lenovo System x3550 M3 Problem Determination And Service Manual page 394

Figure 15. Light path diagnostics panel exposure
Note any LEDs that are lit, and then reinstall the light path diagnostics panel in the server.
Note: When you slide the light path diagnostics panel out of the server to check the LEDs or checkpoint
codes, do not run the server continuously with the light path diagnostics panel outside of the server. The
panel should only be outside of the server a short time. The light path diagnostics panel must remain in
the server when the server is running to ensure proper cooling.
Look at the system service label inside the server cover, which gives an overview of internal components
that correspond to the LEDs on the light path diagnostics panel. This information and the information in
"Light path diagnostics LEDs" on page 384 can often provide enough information to diagnose the error.
3. Remove the server cover and look inside the server for lit LEDs. Certain components inside the server
have LEDs that are lit to indicate the location of a problem. The following illustration shows the LEDs and
connectors on the system board.
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