Setup and Quick Reference Guide 33
Diagnostic Light Codes Before POST

The following table lists the codes for the diagnostic lights that occur before

the computer begins the POST.

Diagnostic Light Codes Before POST
Light Pattern Cause Action
No electrical power is supplied to the
computer.
Connect the computer to its electrical outlet. Ensure that
the front-panel power light is on. If the power light is off,
ensure that the computer is connected to a working
electrical outlet, and then press the power button.
If the problem is still not resolved, contact Dell for
technical assistance.
Normal off condition. Computer is
connected to its electrical outlet.
Ensure that the front-panel power light is on. If the power
light is off, ensure that the computer is connected to a
working electrical outlet, and then press the power button.
When the computer is operating normally, it can be
automatically or remotely started as long as it remains
connected to an electrical outlet. For more information, see
"Power Management" in the User’s Guide.
If the problem is still not resolved, contact Dell for
technical assistance.
Computer is in a reduced power or
"sleep" state.
Use one of the appropriate methods to "wake up" the
computer. See "Power Management" in the User’s Guide.
If the problem is still not resolved, contact Dell for
technical assistance.
BIOS is not executing. See "Reset Corrupted BIOS Settings" in the User’s Guide.
Possible power supply or power cord
failure.
See "Power Problems" in the User’s Guide.
Possible system board failure. Contact Dell for technical assistance.
A B C D
A B C D
A B C D
A B C D
A B C D
A B C D

= yellow

= green

= off