Short answer: unplug the PC, wait for power to settle, then try it once. If nothing happens at all, the power supply is the most likely casualty and the cheapest to replace. If you smell burning, don’t switch it back on.
Right after the surge
- Switch off and unplug the PC, monitor and any extension leads.
- Wait until the power is stable. Surges often come in groups during storms.
- Check for a burning smell or marks on the plug, extension lead or back of the PC.
- Plug straight into a wall socket you know works, and try once.
Read the symptoms
PCWorld sets out a simple way to tell what was damaged:
| What happens | Likely damaged part |
|---|---|
| Nothing at all: no lights, no fans | Power supply |
| Powers on, then turns off again | Motherboard. Try clearing the CMOS first |
| Reaches the BIOS but won’t load Windows, or shows an error | Drive |
Clearing the CMOS means switching off, removing the motherboard’s coin battery for a few minutes, then putting it back. Your motherboard manual shows where it is.
If it’s the power supply
Swapping the power supply is one of the easier repairs on a desktop. Size the new one with the wattage guide. Use only its own cables, and see how to install a power supply.
Don’t test parts with a power supply you suspect was damaged. If it failed badly, it can damage the next part too.
Protect your data first
If you don’t have a backup and the drive may be damaged, recover your files before experimenting further. A data recovery service may be needed for a badly damaged drive.
Protecting your PC next time
- A surge protector. HP says to look for UL 1449 certification on the product itself. A higher joule rating means it can absorb more surge energy.
- A UPS. A battery backup gives you time to save and shut down during a cut, and often includes surge protection. HP advises plugging a UPS straight into the wall, not into a surge protector.
- Network and cable lines. Surges can travel along these too. Some surge protectors have sockets for them.
- Unplug during big storms if you can. HP notes a surge protector lowers the risk but can’t remove it.
Will the warranty cover it?
Check with the maker. Some surge protectors come with equipment cover. Home insurance may also cover surge damage, so check your policy.
- Safe replacement · Tier ACorsair RMx (2024)80 Plus Gold · Fully modular · ATX · 750/850/1000WIncludes fan failure protection and a 10-year warranty from Corsair.Check 850W price
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Questions
Can a power surge kill a power supply?
Yes. The power supply takes the first hit, and it’s often the part that fails.
Does a power supply protect against surges?
Good units have protections, but they aren’t a substitute for a surge protector or UPS.
Should I plug a UPS into a surge protector?
HP advises plugging a UPS straight into the wall unless its maker says otherwise.
My PC works after a surge. Is it fine?
Probably, but watch for random shutdowns or new noises over the next few weeks.
Is it safe to test my PC after a surge?
Try once with the PC plugged straight into the wall. If you smell burning or see damage, don’t.
Sources
- PCWorld: what to do when a power outage or surge damages your PC
- HP: how to protect your computer from power surges
- Corsair: RMx series update (September 2024)
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