Solving Power Problems - HP Compaq 6005 Pro Business PC Maintenance & Service Manual

Solving Power Problems

Common causes and solutions for power problems are listed in the following table.
Table D-2
Power supply shuts down intermittently.
Cause
Power supply will not turn on because of internal power supply
fault.
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. (Beeps stop after fifth iteration but LEDs continue flashing.)
Cause
Processor thermal protection activated:
A fan may be blocked or not turning.
OR
The heat sink is not properly attached to the processor.
Power LED flashes Red four times, once every second, followed by a two second pause, and the computer beeps four
times. (Beeps stop after fifth iteration but LEDs continue flashing.)
Cause
Power failure (power supply is overloaded).
204 Appendix D Troubleshooting Without Diagnostics
Solving Power Problems
Solution
Contact an authorized service provider to replace the power
supply.
Solution
1. Ensure that the computer air vents are not blocked and
the processor cooling fan is running.
2. Open hood, press power button, and see if the processor
fan spins. If the processor fan is not spinning, make sure
the fan's cable is plugged onto the system board header.
3. If fan is plugged in, but is not spinning, then replace the
heat sink/fan assembly.
4. Contact an authorized reseller or service provider.
Solution
1. Open the hood and ensure the 4- or 6-wire power supply
cable is seated into the connector on the system board.
2. Check if a device is causing the problem by removing ALL
attached devices (such as hard 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.
3. Replace the power supply.
4. Replace the system board.