HP Dc5700 HP Compaq dc5700 Business PC Service Reference Guide, 1st Edition - Page 172

Troubleshooting Without Diagnostics Solving Power Supply Problems (Continued) Problem Cause Solution Power LED flashes Red, four times, once every second, followed by a two second pause, and the computer beeps four times. Beeps continue for five iterations after which the LED flashes will continue until the problem is resolved. Power failure (power supply is overloaded). 1. Check that the voltage selector (some models), is set to the appropriate voltage. Proper voltage depends on the region. 2. Open the hood and ensure the 4- or 6-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 causing the failure. Continue adding devices one at a time to ensure all devices are functioning properly. 4. Replace the power supply. 5. Replace the system board. D-8 437804-001 Service Reference Guide, dc5700