How to Check a Bad Power Supply

by Quinten Plummer

A bad power supply can cause any part of your system to fail and can even damage them. When building a new computer, testing the power supply should be done early in the diagnosis process to resolve any start-up issues. Follow the steps in this guide to check your power supply.

Check that your power supply is switched on to the right power rating. For American households, you'll want it set to 120V.

Turn off the power supply off and remove all cables running the computer--except for the power cable.

Unscrew the series of screws located at the back of the case that are securing the side panel of the computer case to the frame. Slide the side panel off and set the screws aside for safekeeping.

Follow the thick braid of cords running from the power supply to the motherboard. The cable will lead you to a wide power port on the motherboard.

With the thumb and forefinger of one hand, take a firm hold of the power port while using the other hand to remove the cable from the port.

Plug the connector head of the power supply cable into the power supply tester. Match the squared bottoms of the cable's micro ports to those of the tester's port. For 20-pin cables, align the connector head to the left of the power supply tester.

Turn the power supply back on. Note the tester's LEDs indicators. They'll indicate whether the power supply is functional.

Items you will need

About the Author

Quinten Plummer began writing professionally in 2008. He has more than six years in the technology field including five years in retail electronics and a year in technical support. Plummer gained his experience in music by producing for various hip-hop acts and as lead guitarist for a band. He now works as a reporter for a daily newspaper.

Photo Credits

  • photo_camera, Baran Ivo