Interpreting POST Diagnostic Front Panel LEDs and
Audible Codes
This section covers the front panel LED codes as well as the audible codes that may occur before or
during POST that do not necessarily have an error code or text message associated with them.
WARNING!
When the computer is plugged into an AC power source, voltage is always applied to the
system board. To reduce the risk of personal injury from electrical shock and/or hot surfaces, be sure
to disconnect the power cord from the wall outlet and allow the internal system components to cool
before touching.
NOTE:
If you see flashing LEDs on a PS/2 keyboard, look for flashing LEDs on the front panel of the
computer and refer to the following table to determine the front panel LED codes.
Recommended actions in the following table are listed in the order in which they should be performed.
Not all diagnostic lights and audible codes are available on all models.
Table C-1
Diagnostic Front Panel LEDs and Audible Codes
Activity
Beeps
Possible Cause
Recommended Action
Green Power LED On.
None
Computer on.
None
Green Power LED flashes
every two seconds.
None
Computer in Suspend to
RAM mode (some models
only) or normal Suspend
mode.
None required. Press any key or move the mouse
to wake the computer.
CPU fan is weak (RPM < 1000)
or not turning. A warning
message is displayed along
with a series of long beeps for
five seconds, then the system
shuts down.
2
Processor thermal
protection activated:
A fan may be blocked or
not turning.
OR
The heatsink/fan
assembly is not properly
attached to the processor.
1.
Ensure that the computer air vents are not
blocked and the processor cooling fan is
running.
2.
Open hood, press power button, and see if
the processor fan spins. If the processor fan
is not spinning, make sure the fan's cable is
plugged onto the system board header.
Ensure the fan is fully/properly seated and
installed.
3.
If fan is plugged in and seated properly, but
is not spinning, then replace processor fan.
4.
Reseat processor heatsink and verify that the
fan assembly is properly attached.
5.
Contact an authorized reseller or service
provider.
Red Power LED flashes five
times, once every second,
followed by a two second
pause. Beeps stop after fifth
iteration but LEDs continue
until problem is solved.
5
Pre-video memory error.
CAUTION:
To avoid damage to the DIMMs or
the system board, you must unplug the computer
power cord before attempting to reseat, install, or
remove a DIMM module.
1.
Reseat DIMMs.
2.
Replace DIMMs one at a time to isolate the
faulty module.
3.
Replace third-party memory with HP
memory.
4.
Replace the system board.
76
Appendix C Troubleshooting
