Desktop Computer Owner's Manual

Troubleshooting Tools 43
Troubleshooting Tools
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 "1," "2," "3," and "4" on
the back panel (see page 57). 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 108 ).
Memory modules are detected, but a
memory failure has occurred.
• If you have two or more memory
modules installed, remove the
modules, reinstall one module (see
page 64), 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 (see page 63).
• If the problem persists, contact Dell
(see page 108).