Troubleshooting 79
12
Troubleshooting

Diagnostic Lights

CAUTION: Before you begin any of the procedures in this section, follow the safety instructions that shipped
with your computer.
Your computer has three keyboard status lights located above the keyboard. During normal operation,
the keyboard status lights display the current status (on or off) of the Num Lock, Caps Lock, and Scroll
Lock features. If the computer starts without error, the lights flash, and then turn off. If the computer
malfunctions, however, you can use the status of the lights to help identify the problem.
NOTE: After the computer completes POST, the Num Lock light may remain on, depending on your BIOS settings.
For more information on using the system setup program, see "System Setup Program" on page103.

Diagnostic Light Codes During POST

To troubleshoot a problem with your computer, read the sequence of the keyboard status lights in order
from left to right (Num Lock, Caps Lock, and then Scroll Lock). If the computer malfunctions the
individual lights display a status of either On , Off , or Flashing .
Light Pattern Problem Description Suggested Resolution
No memory modules
are detected.
• If two or more memory modul es are
installed, remove the modules, then
reinstall one module and restart the
computer. If the computer starts
normally, continue to install
additional memory modules (one at a
time) until you have identified a
faulty module or reinstalled all
modules without error (see "Memory"
on page122).
• If available, install working memory of
the same type into your computer (see
"Memory" on page122).
• If the problem persists, contact Dell
Support.