Troubleshooting Guide

Troubleshooting Guide www.hp.com 2–11
Troubleshooting Without Diagnostics
Power LED flashes Red four
times, once every second,
followed by a two second
pause, and the computer
beeps four times.
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