Light Path Diagnostics - Lenovo System x3550 M3 Problem Determination And Service Manual

Light path diagnostics

Light path diagnostics is a system of LEDs on various external and internal components of the server. When
an error occurs, LEDs are lit throughout the server. 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 that begins
on "Safety" on page v and
If an error occurs, view the light path diagnostics LEDs in the following order:
1. Look at the operator information panel on the front of the server.
• If the information LED is lit, it indicates that information about a suboptimal condition in the server is
available in the IMM system-event log or in the system-error log.
• If the system-error LED is lit, it indicates that an error has occurred; go to
The following illustration shows the operator information panel:
Figure 14. Operator information panel
2. To view the light path diagnostics panel, slide the blue release latch on the operator panel to the left. Pull
forward on the panel until the hinge of the operator panel is free of the server chassis. Then pull down on
the panel so that you can view the light path diagnostics panel information. This reveals the light path
diagnostics panel. Lit LEDs on this panel indicate the type of error that has occurred.
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.
The following illustration shows the light path diagnostics panel:
"Handling static-sensitive devices" on page 419.
Step 2.
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Chapter 3 Diagnostics
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