Help! My Computer Won't Boot After a Power Outage

Written by: Bill Fulks • Edited by: M.S. Smith
Published May 30, 2010

What to do if you have a power surge or outage and your computer won't turn on afterward.

Help! My Computer Won't Start!

If your computer won’t boot after a power spike or power outage, it doesn’t necessarily mean that your system got fried. Often times the reason the computer won’t boot after a power spike is because the system was not properly shut down. There are a few things you can do to get your computer back up and running after a power spike, which we’ll address in this article.

Check the Surge Protector

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Hopefully, you are using a surge protector to plug in your PC and other components. If not, then you’re asking for trouble. It’s not uncommon in the event of a power spike or power outage for the surge protector to cut itself off. Your surge protector or power strip should have some kind of power button on it and usually there is a light indicator. All you have to do is flip the switch off and back on, then try turning on your computer or anything else plugged in through that strip. It could be that your surge strip got fried while protecting your computer, which is what it’s supposed to do.

Unplug the Power

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The power button on the front of most computers is what you call a ‘soft button’. This means that pressing the button ties it into some software or command that runs, and it’s not a hard on/off button like a light switch on a wall. In the event of a power spike or power surge, the soft button gets tripped up because the computer wasn’t shut down properly. When you press the button expecting the PC to turn back on, the software command it might try sending to the OS could be a shut down command, so nothing works.

In order to reset the soft button, as well as the computer, the best method is to simply unplug the power cable from the back of the computer. If it’s a laptop or notebook PC, then you may also need to unplug the battery. Leave the machine unplugged for a good 30 seconds, then plug the cable back in and try to turn it back on. You may also have to press and hold down the power button for as long as ten seconds before the system turns back on.

Reset Power Supply

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The power supply is the box mounted inside the back of your computer where the power cable plugs in. It is what takes the AC power and divides it between the internal components of your computer, such as the motherboard, hard drive, video card, and so on. If your computer won’t boot after a power spike and you’ve already unplugged and plugged back in the power cable, you may need to also reset the power supply.

Some power supplies will have a switch on them, and you can just flip the switch off and then back on again to reset the power. You can try doing this with or without the power cable plugged in. If that doesn’t work, another thing you can try is changing the volt selection by flipping that switch (see the red switch in the image to the right) back and forth with a flathead screwdriver. That seems to work on some older machines, but do it with the power cable unplugged.