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 operator information 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, if 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 and Handling static-sensitive devices.

If an error occurs, view the light path diagnostics LEDs and look at the operator information panel on the front of the server.

The following table describes the LEDs on the operator information panel and suggested actions to correct the detected problems.

Table 1. Light path diagnostics: LED status and actions.

Three-column table for documenting the LED, description, and action.

LED	Description	Action
System-locator LED (blue)	This LED is used as a presence detection LED. You can use Systems Director or IMM2.1 to light this LED remotely.	Use this LED to locate the server among other servers visually.
Check log LED (amber)	LED on: An error has occurred and cannot be isolated without performing certain procedures.	Check the IMM2.1 event log and the system-error log for information about the error. Save the log if necessary and clear the log afterward.
System-error LED (amber)	LED on: An error has occurred.	Check the system-locator LED and check log LED and follow the instructions. Check the IMM2.1 event log and the system-error log for information about the error. Save the log if necessary and clear the log afterward.