How to Troubleshoot an HP Computer That Will Not Power Up

by Katie Strzeszewski

There are multiple reasons why an HP computer might not power up. Some problems require easy, in-home fixes, some problems can be solved by the user but require extra supplies, and some problems are best left to the professionals. The troubleshooting process will help determine what kind of problem you are experiencing and what kind of repair is necessary.

How to Troubleshoot an HP Computer that will Not Power Up

Inspect any surge protectors and outlets. Check whether the surge protector needs to be reset; if so, reset it. If that does not work, try plugging the computer (or the surge protector) into a different outlet. Also, check the back of your computer to see if there is a secondary power switch there. If so, make sure it is in the "On" position.

Using a different, known-good power cord to plug in the computer, to determine whether the original cord was causing the problem.

If you are comfortable opening the computer, remove the side panel. Search on the computer's motherboard for the 20-pin and the 4-pin plugs. Unplug those from the motherboard, then locate a free line from the power supply. Plug the 20-pin, the 4-pin, and the extra line into a power supply tester. (See Tips and the link in resources.) If the power supply tester does not read properly, your computer has a bad power supply, which can be replaced by you personally (if you are comfortable doing so) or can be replaced in a local repair shop. If you are not comfortable doing this work on your own, bring the computer to a professional for this test.

If the power supply tester from Step 3 indicates the power supply is good, the problem is with either the CPU or the motherboard and the computer needs to be brought to a professional to have the faulty part replaced.


  • check If you are comfortable enough to open a computer to work on Step 3, but don't know how to use or read the power supply tester, the necessary instructions are included in the tester's packaging.


  • close If your computer is within a manufacturer's warranty or an extended service plan, do not open the computer yourself, as doing so will void any such warranties. You can still troubleshoot through Steps 1 and 2, but leave 3 and 4 for the professionals.
  • close If you get to Step 4 and the issue is the CPU or the motherboard, it is usually more financially feasible to simply replace the computer, as CPU and motherboard replacements are expensive.
  • close Make sure the power cord is disconnected before doing anything inside the computer case. Parts of the system may be powered even when the system is off. You could risk personal injury or damage to circuitry if the power is not disconnected.
  • close Static electricity can damage electronic parts. Ground yourself by touching a metal part of the computer chassis, or use an antistatic wrist strap, before touching any internal computer part.

Items you will need

About the Author

Katie Strzeszewski has been writing professionally since 2003 and holds a Bachelor of Arts in professional writing and English secondary education from York College of Pennsylvania. Strzeszewski spent two years performing computer repair for Geek Squad, currently works for men's clothier Paul Fredrick and is also a competitive West Coast Swing and Hustle dancer.

Photo Credits

  • photo_camera motherboard image by Horticulture from