Troubleshoot a Computer That Won't Turn On

Troubleshoot a Computer That Won't Turn On

It's a dreadful way to start a day - you press the power button on your computer and nothing happens. Few computer problems are more frustrating than when your computer won't boot.

There are many reasons why a computer won't turn on and often very few clues about what might be the problem. The only symptom is usually the simple fact that "nothing works" which isn't much to go on.

Add to this the fact that whatever is wrong could be an expensive part of your PC to replace - like the motherboard or CPU.

Do not fear because all may not be lost! Follow these steps to determine why your computer won't turn on.
Difficulty: Average
Time Required: Anywhere from 10 minutes to a few hours or more depending on why the computer won't turn on
Here's How:

1.

Try to relax! There's a good chance you can figure out exactly why your computer won't start and then get it back up and running.

I don't usually a troubleshooting guide with the same advice a psychologist might give a client, but when faced with a computer that won't start most people tend to panic, worried that all the data on their PC is gone forever.

It's true that the most common reason a computer won't start is because a piece of hardware has failed or is causing a problem. However, that failing hardware isn't usually a hard drive, meaning that all your data is probably safe - just not accessible.
2.

Computer shows no sign of power at all. Try these steps if your computer will not turn on and is showing no sign at all of receiving power - no fans running and no lights on the computer case.

Important: You may or may not see a light on the back of your PC depending on the kind of power supply you have and the exact cause of the problem.

Note: Don't worry about the monitor yet. If the computer is not turning on because of a power issue then the monitor certainly can't display anything from the computer. Your monitor light will likely be amber/yellow if your computer has stopped sending information to it.
3.

Computer turns on for a few seconds and then turns off. Follow these steps if, when you turn your computer on, it promptly powers back off.

You'll probably hear the fans inside your computer turn on, see the lights on the front of your computer turn on or flash, and then it will all stop - always before the boot process is complete. You may or may not also hear beeping coming from inside your PC.

Note: As in the previous scenario, don't worry about what state your monitor is in. You may have a monitor issue as well but it's not possible to troubleshoot it quite yet.
4.

Computer turns on but nothing shows on screen. If your computer seems to be receiving power after turning it on but you don't see anything on your monitor, try these troubleshooting steps.

In these situations, the power lights will stay on, you'll likely hear the fans inside your PC running, and you may or may not hear one or more beeps coming from the computer.

This situation is probably the most common in my experience working with computers that won't start. Unfortunately it's also one of the most difficult to troubleshoot.
5.

Computer turns on but stops booting during the POST. Use this guide when your computer powers on, shows at least some information on the monitor, but then stops for any reason during the Power On Self Test.

Use this troubleshooting guide primarily if you receive a BIOS error message during the POST but also if your PC locks up during the POST without an on-screen message.

Important: If you're having an issue during the loading of the operating system, which occurs after the Power On Self Test is complete, see Step 6.
6.

Computer turns on but an error message prevents the operating system from loading completely. If your computer begins to load Windows but then stops booting and displays an error message, you're best bet is to troubleshoot the problem based on the specific error message.

If you don't find instructions on resolving the specific error you see, see the first tip below for information on requesting more assistance from the forum on this site.