Dell Precision R5500 (Early 2011) - Manual (Page 77)

Light Pattern Problem Description Troubleshooting Steps
Diagnostic LEDs Power Button LED
connections from
the system board,
then press and hold
the power supply
button. If it
illuminates, there
could be a problem
with the system
board.
• If the LED still does
not illuminate, the
problem is with the
power supply.
Memory modules are
detected, but a memory
power failure has occurred.
• If two or more
memory modules
are installed,
remove the
modules, then re-
install one module
and re-start the
computer. If the
computer starts
normally, continue
to install additional
memory modules
(one at a time) until
you have identified
a faulty module or
reinstalled all
modules without
error. If only one
memory module is
installed, try moving
it to a different
DIMM connector
and re-start the
computer.
• If available, install
verified working
memory of the same
type into your
computer.
A possible CPU or system
board failure has occurred. Replace the CPU with a
known good CPU. If the
computer still fails to boot,
inspect the CPU socket for
damage.
BIOS may be corrupt or
missing. The computer hardware is
operating normally but the
BIOS may be corrupt or
missing.
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