Tools to help solve problems, Diagnostic lights, Diagnostic light codes before post – Dell Precision 490 User Manual
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Tools to Help Solve Problems
Dell Precision™ Workstation 490 User's Guide
Restoring Your Operating System
Software and Hardware Incompatibilities
Diagnostic Lights
To help you troubleshoot a problem, your computer has four lights labeled "1," "2," "3," and "4" on the front. The lights can be "off" or green. When the
computer starts normally, the lights flash. If the computer malfunctions, the pattern of the lights and also that of the power button help to identify the
problem. These lights also indicate sleep states.
Diagnostic Light Codes Before POST
CAUTION:
Before you begin any of the procedures in this section, follow the safety instructions in the Product Information Guide.
Diagnostic
Lights
Power
Light
Problem Description
Suggested Resolution
off
No electrical power is supplied to the
computer.
Connect the computer to an 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 (see
Contacting Dell
).
off
The computer is in a normal off condition;
the computer is connected to an electrical
outlet.
Press the power button to turn the computer on.
If the computer does not turn on, 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 (see
Contacting Dell
).
blinking
green
The computer is in a reduced power or
"sleep" state.
Use one of the appropriate methods to "wake up" the computer. See
Advanced
Features
.
If the problem is not resolved and you are trying to wake the computer with a
USB mouse or keyboard, substitute the mouse or keyboard with a working PS/2
mouse or keyboard and then try to wake the computer.
blinking
green
The computer is in a reduced power or
"sleep" state.
Use one of the appropriate methods to "wake up" the computer. See
Advanced
Features
.
If the problem is not resolved and you are trying to wake the computer with a
USB mouse or keyboard, substitute the mouse or keyboard with a working PS/2
mouse or keyboard and then try to wake the computer.
(blinking)
amber
The BIOS is not executing.
Ensure that the processor is seated correctly and restart the computer (see
Processor
).
If the problem is still not resolved, contact Dell for technical assistance (see
Contacting Dell
).
(blinking)
blinking
amber
A possible power supply or power cable
failure has occurred.
Perform the procedure in
Power Problems
.
If the problem is still not resolved, contact Dell for technical assistance (see
Contacting Dell
).
(blinking)
amber
A possible system board failure has
occurred.
Contact Dell for technical assistance (see
Contacting Dell
).
(blinking)
amber
A processor mismatch exists.
See
Troubleshooting Tips
, then refer to
Memory Problems
and
Power Problems
.