54 Advanced Troubleshooting
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Diagnostic Lights

To help you troubleshoot a problem, your computer is equipped with four lights on the back

panel labeled "A," "B," "C," and "D" (see page 70). These lights can be yellow or green.

When the computer starts normally, the lights flash. After the computer starts, the lights

remain green. If the computer malfunctions, the color and sequence of the lights identify

the problem.

CAUTION: Before you begin any of the procedures in this section, follow the
safety instructions on page 12.
Light Pattern Problem
Description
Suggested Resolution
Memory modules are
detected, but a
memory failure has
occurred.
• If you have one memory module installed,
reinstall it (see page83) and restart the
computer.
• If you have two or more memory modules
installed, remove the modules, reinstall one
module (see page83), and then restart the
computer. If the computer starts normally,
reinstall an additional module. Continue
until you have identified a faulty connector
or reinstalled all modules without error.
• If available, install properly working memory
of the same type into your computer (see
page83).
• If the problem persists, contact Dell (see
page100).
Memory modules are
detected, but a
memory
configuration or
compatibility error
exists.
• Ensure that there are no special memory
module/memory connector placement
requirements (see page83).
• Verify that the memory modules that you are
installing are compatible with your computer
(see page93).
• If the problem persists, contact Dell (see
page100).
YYGG
ABCD
GYGY
ABCD