Troubleshooting Guide
A–14 www.hp.com Troubleshooting Guide
POST Error Messages
Red Power LED 
flashes two times, 
once every second, 
followed by a two 
second pause.
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. Reboot the system and observe if 
there are any POST messages 
stating that one or more of the fans 
are not detected. If a fan is not 
detected during POST, unplug the 
unit, open the chassis and ensure 
that the all the fans are plugged in 
correctly.
3. If fan is plugged in and seated 
properly, and the POST message 
still appears, then replace the 
processor fan.
4. Reseat processor heatsink and 
verify that the fan assembly is 
properly attached. See the 
appropriate Service Reference 
Guide for instructions on how to 
reinstall the heatsink. Correct 
heatsink installation is critical to 
proper system operation.
5. Contact an authorized reseller or 
service provider.
Red Power LED 
flashes three times, 
once every second, 
followed by a two 
second pause.
3 Processor not 
installed (not an 
indicator of bad 
processor).
1. Check to see that the processor is 
present.
2. Reseat the processor.
Diagnostic Front Panel LEDs and Audible Codes (Continued)
Activity Beeps Possible Cause Recommended Action










