Power Surge

How to check your PC for damage after a power surge. How to fix your PC after a power surge. Visit Upgrade Advisor for advice on PC upgrades and repairs.

Power surges are a problem more often associated with countries that have less reliable electric networks than we do here in the UK. But power surges do happen in the UK, from time to time. And if your PC is switched on and connected to the mains when such an event takes place, you'll likely see some damage. In all likelihood the damage will seem terminal - your PC will just not switch on.

But it may not be all that bad. Indeed, the chances are that your PC's PSU (power supply unit) will need to be replaced, but if you are lucky everything else will remain unscathed.

For the record, a power surge is a damaging spike of voltage through the elctrical network. When they do occur they are often caused by lightning strikes or problems with the national grid.

Here we show you how to check and repair your PC after a power surge. But first, a couple of tips on how to avoid such damage in the first place. As we've stated above, power surges are rare in the UK, so you can make an informed decision on whether it is worth your while.

Prevent power surge damage to PC

Belkin SurgeMaster The simplest procedure is to unplug your PC when you boot it down and switch off. These days most PCs spend their lives asleep and plugged in rather than fully switched off, but if you want to avoid the results of power surges get into the habit of physically unplugging your PC when you finish working on it. Of course this won't help if thunder strikes when you are in the process of doing your annual tax return, and there's not much point in a PC that you never switch on.

So a more effective but expensive alternative is to use an anti-surge power strip. These cost more than your average power strip, but not outrageously so. You can pick up the Belkin Surgemaster six-way power strip for less than £20, for instance.

But let's assume that you have already suffered the outragous fortune of a PC-breaking power surge...

Check and fix a PC after power surge

We're going to assume that your PC just won't switch on. Don't panic. All is not lost. (If you are just concerned about damage but everything seems to be working fine, you can still follow the procedure outlined below. But with a glad heart.)

Before you do anything unplug the PC and then the power strip - in that order. Now plug in the monitor directly to the mains. If that works you can set it aside safe in the knowledge the problem is the PC itself.

Now you need to open up your PC's case. This will likely involve unscrewing some screws at the edge of the case, but consult your PC's manual if you are unsure (although this seems like a huge deal to non-upgraders, it really is surprisingly simple).

Now imagine that you are in your car and have broken down on the hard shoulder of the M1. What would you do? That's right, look under the bonnet for anything that looks obviously wrong, and then shake your head and give up. Do that here: look for anything scorched or damaged.

If you can see and identify any component that is obviously broken, it needs to be replaced. [Awards himself gold star for obvious advice.] Now depending on your level of expertise you should replace that component, but not before you also replace the PSU. If you know that you have been the victim of a power surge that has damaged your PC, you need a new power supply unit.

Here's our piece offering detailed advice on how to check and replace your PC's power supply.

Once you'd replaced the PSU you can connect the PC and monitor, and connect both to the mains. Now look closely - if everything is working fine you are in clover. But because you know the monitor is okay, if the PC powers up and nothing appears on the screen you have a problem with the PC's graphics card. And if the PC doesn't power up at all you likely have a problem with the motherboard.

Again, you may be comfortable doing these tasks. We have advice here:

But if this seems beyond you, seek professional help. For your PC. (Unless the stress has really taken over.)