Diagnostic Lights - Dell OptiPlex 745c Quick Reference Manual

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.
Memory modules are detected, but a memory
failure has occurred.
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.
• If you have one memory module installed,
reinstall it and restart the computer. For
information on reinstalling memory
modules, see your online User's Guide.
• If you have two or more memory modules
installed, remove the modules, reinstall
one module, and then restart the computer.
If the computer starts normally, reinstall
an additional module. Continue until
you have identified a faulty module or
reinstalled all modules without error.
• If available, install properly working
memory of the same type into your
computer.
• If the problem persists, contact Dell.
For information on contacting Dell, see
your online User's Guide.
Quick Reference Guide
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