Dell Dimension 8400 - Manual (Page 49)

Advanced Troubleshooting
49
Advanced Troubleshooting
Diagnostic Lights
CAUTION:
Before you begin any of the procedures in this section, follow the safety instructions
located in the Product Information Guide.
To help you troubleshoot a problem, your computer has four lights labeled "A," "B," "C," and "D" on
the back panel (see page 63). The lights can be yellow or green. When the computer starts
normally, the lights flash. After the computer starts, all four lights display solid green. If the
computer malfunctions, the color and sequence of the lights identify the problem.
Light Pattern Problem Description Suggested Resolution
The computer is in a normal off condition or a
possible pre-BIOS failure has occurred. Plug the computer into a working electrical
outlet and press the power button.
A possible processor failure has occurred. Contact Dell (see page 123).
A B C D
A B C D
= yellow
= green
= off