76 Troubleshooting
• If the power light is steady amber, a device may be malfunctioning or 
incorrectly installed.
– Remove and then reinstall the memory modules (see "Memory" on 
page 104).
– Remove and then reinstall any cards (see "Cards" on page 109).
• Eliminate interference. Some possible causes of interference are:
– Power, keyboard, and mouse extension cables
– Too many devices on a power strip
– Multiple power strips connected to the same electrical outlet
Diagnostic Lights
  CAUTION: Before you begin any of the procedures in this section, follow the 
safety instructions in the Product Information Guide.
To help troubleshoot a problem, your computer has four blue lights labeled 1, 
2, 3, and 4 on the top bezel (see "Front View" on page 15). When the 
computer starts normally, the lights flash before turning off. If the computer 
malfunctions, the sequence of the lights help to identify the problem.
  NOTE: After the computer completes POST, all four lights turn off before booting to 
the operating system.
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 system 
successfully boots to the 
operating system.
• Plug the computer into a 
working electrical outlet (see 
"Power Problems" on page 69).
• If the problem persists, contact 
Dell (see 
"Contacting Dell
" on 
page 200).
A possible processor failure 
has occurred.
• Reseat the processor (see 
"Processor" on page 154).
• If the problem persists, contact 
Dell (see 
"Contacting Dell
" on 
page 200).
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