How to Check Power Supply on a Computer

The power supply on a computer is the main power source. Without a power supply, the computer will not function. This device sends an electrical current from the outlet into the motherboard to complete a circuit. If the power supply is not executing properly, the motherboard will not have enough power to control all of the components. Checking a power supply is important. If the supply is not performing at full power, this could damage the other computer devices.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Computer tower components
• Phillips screwdriver

Install the Power Supply

1. Unfasten the screws on the right panel of the tower. Pull the panel off. Lay the tower flat on the ground with the open side facing up.

2. Remove the current power supply. Wiggle the white connectors from the devices. This includes the motherboard, CD/DVD ROM, hard or floppy drives. Unscrew the supply from the case and take out.

3. Insert the test power supply. Plug the large white connector into the motherboard. This is near the fan/processor. Push in; this may be a tight fit. Enter the remaining white connectors into the other movable devices as mentioned in Step 2.

Check the Power Supply

4. Plug the power cord into the supply. Press the large "On" button in the front of the tower.

5. Listen closely to the power supply. The main and any secondary fans should engage. If the fan does not turn on, you need to replace the power supply. If it does, continue to Step 3.

6. Listen and look at the PC while the computer boots. The hard drive, CD/DVD ROM and floppy lights on the front of the computer will light up. If the lights do not turn on or the computer does not boot up, the power supply more than likely needs a replacement.

Tips & Warnings

• Skip Section One if you are testing the current power supply in the computer. Clean the dust out of the power supply before testing. Debris may cause the supply to function incorrectly. You do not need to screw the power supply in to test it. Lay it on the side of the tower instead. Test the power supply on a known working motherboard.