IBM 7383, Installation And Service Manual, Page: 154 / 488

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 along the path of the front panel, the light path diagnostics
panel, 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 37.
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.
v
If the check log LED is lit, it indicates that an error or multiple errors have
occurred. The sources of the errors cannot be isolated or concluded by
observing the light path diagnostics LEDs directly. A further investigation
into IMM2 system-event log or system-error log might be required.
v If the system-error LED is lit, it indicates that an error has occurred; go to
step 2.
The following illustration shows the operator information panel.
The following table describes the LEDs on the operator information panel and
suggested actions to correct the detected problems.
Table 10. The suggested actions to correct the detected problem for each LED light
v Follow the suggested actions in the order in which they are listed in the Action column until the problem is
solved.
v
If an action step is preceded by “(Trained technician only)”, that step must be performed only by a trained
technician.
v Go to the IBM support website at http://www.ibm.com/supportportal to check for technical information, hints,
tips, and new device drivers or to submit a request for information.
LED Description Action
System locator (blue) Use this LED to visually located the server
among other servers. You can use IBM
Systems Director or IMM2 to light this
LED remotely.
Figure 30. Operator information panel
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System x3500 M4 Type 7383: Installation and Service Guide