Dell Precision T3912, Quick Reference Manual

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Quick Reference Guide
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Diagnostic Light Codes Before POST
Light Pattern Problem Description Suggested Resolution
off
off
off
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.
yellow
off
off
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.
yellow
yellow
off
off
The computer is in a reduced
power or "sleep" state. Use one of the appropriate methods to "wake up" the
computer. See "Advanced Features" in the
User’s Guide .
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.
yellow
yellow
yellow
off
The BIOS is not executing. Ensure that the processor is seated correctly and restart
the computer.
If the problem is still not resolved, contact Dell for
technical assistance.
off
yellow
off
off
A possible power supply or
power cable failure
has occurred. Perform the procedure in "Power Problems" in the
User’s Guide .
If the problem is still not resolved, contact Dell for
technical assistance.
off
off
yellow
off
A possible system board
failure has occurred. 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