How to fix a computer that won’t turn on

Last Updated on August 6, 2018 by Dave Farquhar

When a computer won’t turn on, it’s usually a simple repair you can do yourself. Frequently it doesn’t cost anything and doesn’t require any parts. If you do need parts, you can expect it to cost $70 or less and get it done in less than an hour. Here’s how to fix a computer that won’t turn on.

How to fix a desktop computer that won’t turn on

First things first: Try just unplugging the computer for a about 15 seconds or so, then plugging it back in and turning it on. For a lot of computers, particularly desktop computers, that’s all it takes. If you want to be really safe, hold down the power button for a few seconds while it’s unplugged. About 15 seconds should be more than enough.

Some computers are more prone to this than others, but I’ve used this fix a lot over the years.

Check the power button

If a desktop computer won’t turn on after that, it’s probably the power supply. But let’s check one other thing first. Pop open the case and check the lead from the power button to the computer’s motherboard. If that’s unplugged, then of course the power switch won’t work. There’s usually no good reason for that to come loose, but it’s always worth checking the simple things.

Power buttons rarely go bad, but it’s certainly possible. To test that possibility, plug the computer back in, then unplug the lead from the power button and very carefully short the two pins that the power button connected to. I use a small screwdriver. If the computer comes to life, you’ve got a bad power button. Unfortunately, it may be more practical to transplant the guts of the computer into a new case than to replace the power button. Or if there’s an extra button on the case, such as a reset button, you can wire the reset button to that lead to give yourself a working power button.

If your computer is a name-brand system, you may be able to find a replacement front panel on Ebay and swap it out to regain a functioning power button.

Check the power supply

I’ve covered a cheap way to test a standard ATX power supply before. All you need is a paper clip. If the power supply is dead, it’s a cheap repair. Take a photo so you can see where everything goes, then unplug all of the connectors and unbolt the power supply. Take it to a nearby computer store you trust and buy a replacement. You may end up with an off-brand, so here’s everything you need to know about buying off-brand power supplies. Bring it home and plug it back in.

If you’re uncomfortable swapping a power supply, a repair shop ought to be able to do it for you. Power supplies aren’t an expensive component, and the swap only takes a few minutes.

And when it comes to desktops at least, that’s how to fix a computer that won’t turn on.

How to fix a laptop computer that won’t turn on

If your computer is a laptop, that’s easy too. My method of fixing an HP Elitebook is one of the most popular things I ever wrote. That method works on any other brand of laptop too. It just happens that at the time I wrote that piece, I worked somewhere that had HP Elitebooks.

In a nutshell, just unplug the power adapter, pull the battery, and then hold down the power button for about 15 seconds. Then plug the battery back in and plug in the AC adapter.

With newer, higher-end laptops, sometimes the battery isn’t removable. For those, you have to do an alternative fix. Hold down the power button for a good 30-60 seconds to try to force a reset. Try this both with the AC adapter plugged in and not plugged in.

When it comes to laptop computers, one of these two fixes almost always work. I’ve been doing this for years and can’t tell you the last time it didn’t work.

The last resort: the AC adapter

The problem is rarely the AC adapter. AC adapters in general tend to be pretty low quality, but first-party laptop AC adapters tend to be pretty robust in my experience. But if you’ve tried the fix above and the laptop still won’t turn on, you can try another AC adapter if it still won’t power on or charge. Stick with like brands if at all possible, and make sure the voltage and wattage match. Dell and HP don’t want you using their adapters on each other’s laptops.

If you find or borrow a suitable AC adapter and the laptop still doesn’t work, you may need to take it to a reputable repair shop to see what they can do for you.

And when it comes to laptops, that’s how to fix a computer that won’t turn on.

How to fix a computer that won’t turn on: In conclusion

That’s pretty much it. More often than not, removing power and discharging the computer by holding the power button fixes the problem. If it’s a hardware problem, unfortunately desktops have a lot more options as far as fixing them yourself.