A loose or unplugged power cable is one of the top reasons a computer won’t turn on.

Plug your tablet, laptop, or desktopdirectly into the wallif it’s not already.

You’ll likely need to replace your surge protector or other power distribution devices.

If nothing improves, continue troubleshooting with the computer plugged into the wall to keep things simple.

Perform a “lamp test"to verify power is being provided from the wall.

We don’t recommend testing an outlet with a multimeter.

Putting a real “load” on the outlet, like a lamp, is a better option.

Verify that thepower supply voltage switchis correctly set if you’re on a desktop.

Remove the main battery in the laptop or tabletand try using AC power only.

Yes, it’s perfectly fine to run your portable computer without the battery installed.

Carefully inspect the power receptacle on the laptop or tablet for damage.

Replace the computer’s power cable or AC adapter.

On a desktop, this is the power cable that runs between the computer case and the power source.

A bad AC adapter is a common reason why tablets and laptops won’t turn on at all.

Confirm that the power switch is connected to the motherboard if using a desktop.

Most case switches are connected to the motherboard via a red and black twisted pair of wires.

Test your power supplyif you’re using a desktop PC.

You should, however, test it to be sure.

There’s no reason to replace a working piece of hardware when testing it is pretty straightforward.

Unplug your rig immediately and skip the testing.

Replace your power supply if it fails your testing, or you experience the symptoms I just described.

I bring this up again to help stress thatyou should not skip this troubleshooting step.

The following few causes to consider aren’t nearly as common.

This step goes for desktop computers only.

Replace your motherboard if you’re using a desktop.

Be sure you’ve exhausted all of the other troubleshooting advice I’ve given above before replacing your motherboard.

Replacing the motherboard is probably the right course of action with a laptop or tablet as well.

Still, motherboards in these types of computers are very rarely user-replaceable.

The next best course of action for you is to seek a professional computer service.

At this point, your PC should be working again.

FAQ

If yourmonitor doesn’t turn on, you should look at a few things.

test whether there is a power light on the monitor and PC and that the power is connected securely.

your setup may be having problems resuming from Hibernation or Standby/Sleep mode.

Look at both hardware damage and software issues.

If you don’t see any physical damage, look at the drivers controlling the fan or evenBIOS controls.