How to Diagnose a Failed PC Power Supply

A failed PC internal power supply leaves your PC completely dead. Diagnosing the power supply as the culprit of a dead system requires opening the computer and manipulating some of the internal components. A professional diagnosis for any computer problem is expensive, so save yourself a lot of money and verify the internal power supply is the reason your PC is not working.

Difficulty: Moderately Challenging

Instructions

1. Plug the PC into an electrical outlet rather than relying on a battery to power up the system.

2. Eliminate a faulty electrical cord as the culprit. Examine the cord that runs from the PC to the wall outlet. Determine whether there are any indicator lights within the cord itself to identify functionality. If there is such a light and it is not lit when plugged in, the problem may be with the cord and not the PC.

3. Try to turn the PC on. To diagnose the internal power supply as the culprit, it is essential that there be no sound or monitor activity whatsoever. The PC needs to be completely dead.

4. Unplug the PC.

5. Open the PC.

6. Identify the power supply. It will be a metal box containing a power cord receptacle (where you plug in the PC's power cord) and a small fan. It is usually located in a corner of a desktop PC.

7. Remove the power supply plug from the motherboard.

8. Insert a paperclip into the terminals (usually colored black and green) of the power supply plug.

9. Plug the PC directly into a wall outlet. Do not use an extension cord.

10. Press the power button on the computer.

11. Examine the PC fan inside the power supply to see if it is spinning. If it is not, then you have diagnosed a failed power supply.

Tips & Warnings

• If, after you remove the power supply plug from the mother board, insert a paperclip into the plug's terminals and press the power button, the fan inside the power supply does spin, the problem is a failed motherboard rather than a failed power supply.