Troubleshooting Guide
2–12 www.hp.com Troubleshooting Guide
Troubleshooting Without Diagnostics
Power LED flashes Red four 
times, once every second, 
followed by a two-second 
pause. The Power LED will 
continue flashing until the 
problem is resolved.
Power failure (power 
supply is overloaded).
1. Check that the voltage selector, 
located on the rear of the power 
supply (some models), is set to 
the appropriate voltage. Proper 
voltage setting depends on your 
region.
2. Open the hood and ensure the 
4-wire power supply cable is 
seated into the connector on the 
system board.
3. Check if a device is causing the 
problem by removing ALL 
attached devices (such as hard, 
diskette, or optical drives, and 
expansion cards). Power on the 
system. If the system enters the 
POST, then power off and 
replace one device at a time 
and repeat this procedure until 
failure occurs. Replace the 
device that is causing the 
failure. Continue adding devices 
one at a time to ensure all 
devices are functioning 
properly.
4. Contact an authorized service 
provider to replace the power 
supply.
5. Replace the system board.
Solving Power Supply Problems (Continued)
Problem Cause Solution










