Dell Precision R5500 Owner's Manual page 77

Light Pattern
Diagnostic LEDs Power Button LED
Problem Description
The computer is
either turned off or
is not receiving
power.
A possible system
board failure has
occurred.
Troubleshooting
Steps
• Re-seat the
power cable in
the power
connector at the
back of the
computer and
the electrical
outlet.
• Bypass power
strips, power
extension
cables, and
other power
protection
devices to verify
that the
computer turns
on properly.
• Ensure that any
power strips
being used are
plugged into an
electrical outlet
and are turned
on.
• Ensure that the
electrical outlet
is working by
testing it with
another device,
such as a lamp.
• Ensure that the
main power
cable and front
panel cable are
securely
connected to
the system
board.
Unplug the
computer. Allow
one minute for the
power to drain. Plug
the computer into a
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