Dell OptiPlex 745 - Manual (Page 50)

50
Quick Reference Guide
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.
Solid green power
light, no beep code
and no video during
POST The monitor or the graphics card may
be faulty or incorrectly installed. Check Diagnostic Lights to see if the specific
problem is identified.
Solid green power
light and no beep
code, but the
computer locks up
during POST An integrated system board device
may be faulty. Check Diagnostic Lights to see if the specific
problem is identified. If the problem is not
identified, contact Dell for technical
assistance. For information on contacting Dell,
see your online
User’s Guide.
Light Pattern Problem Description Suggested Resolution
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.
Plug the computer into a working
electrical outlet and press the power
button.
A possible BIOS failure has occurred; the
computer is in recovery mode. Run the BIOS Recovery utility, wait for
recovery completion, and then restart the
computer.
A possible processor failure has occurred. Reinstall the processor and restart the
computer. For information on reinstalling
the processor, see your online
User’s Guide.
Power Light Problem Description Suggested Resolution