Troubleshooting Guide
Troubleshooting Guide www.hp.com 2–11
Troubleshooting Without Diagnostics
Computer powered off 
automatically and the 
Power LED flashes Red two 
times, once every second, 
followed by a two second 
pause, and the computer 
beeps two times.
Processor thermal 
protection activated:
A fan may be blocked 
or not turning.
OR 
The heatsink 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.
Solving Power Supply Problems (Continued)
Problem Cause Solution










