Diagnostic Lights
CAUTION:
Before you begin any of the procedures in this section, follow the safety instructions in the Product
Information Guide.
To help you troubleshoot a problem, your computer has four lights labeled "1," "2," "3," and "4" on the
front or back panel. The lights can be "off" or green. When the computer starts normally, the patterns or
codes on the lights change as the boot process completes. If the POST portion of system boot completes
successfully, all four lights display solid green for a short time, and then turn off.
If the computer malfunctions during the POST process, the pattern displayed on the LEDs may help
identify where in the process the computer halted. If the computer malfunctions after a successful
POST, the diagnostic lights do not indicate the cause of the problem.
NOTE:
The orientation of the diagnostic lights may vary depending on the system type. The diagnostic lights can be
either vertically or horizontally oriented.
Light Pattern
Problem Description
The computer is in a normal "off"
condition, or a possible pre-BIOS failure
has occurred.
The diagnostic lights are not lit after the
computer successfully boots to the
operating system.
A possible BIOS failure has occurred; the
computer is in recovery mode.
A possible processor failure has occurred.
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Quick Reference Guide
Suggested Resolution
Plug the computer into a working electrical
outlet and press the power button.
Run the BIOS Recovery utility, wait for
recovery completion, and then restart the
computer.
Reinstall the processor and restart the
computer. For information on reinstalling the
processor, see your online User's Guide.