Dell Precision T7400 - Manual (Page 26)

26 Quick Reference Guide
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 lights labeled 1, 2, 3, and
4 on the front panel (see "Front View (Tower Orientation)" on page 18). When
the computer starts normally, the lights flash, and then turn off. If the computer
malfunctions, use the sequence of the lights to help identify the problem.
NOTE: After the computer completes POST, all four lights turn off before booting to
the operating system.
Diagnostic Light Codes During POST
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 BIOS
failure has occurred;
the computer is in the
recovery mode. • Run the BIOS Recovery utility, wait
for recovery completion, and then
restart the computer.
• If the problem persists, contact Dell
(see "Contacting Dell" in your
User’s Guide).
A possible processor
failure has occurred. • Reseat the processor (see "Processor"
in your User’s Guide).
• If the problem persists, contact Dell
(see "Contacting Dell" in your
User’s Guide).