Lightning or a power surge fried your computer? What to do and what can be saved

Summer storms arrive fast, and a single strike or a surge on the grid can destroy a computer, NAS and router in an instant. Lightning does not even have to hit the house directly. We will show you what to do right after a hit, what usually burns out and, most importantly, whether your data can be saved.

How surges and lightning destroy electronics

Damage is not caused only by a direct lightning strike. A surge spike reaches devices through several paths:

• Through the power socket. The most common path. A strike into the line, even kilometres away, sends a short but destructive voltage spike into the wiring.
• Through a data cable. The internet (network), antenna or phone cable brings the surge straight into the router, modem or the computer’s network card.
• Without a direct hit. Lightning that strikes nearby induces a surge. Electronics can also be damaged by a sudden return of power after an outage.

Right after a hit: what to do and what not to

• If the storm is still going and the computer works, unplug it from the socket and from the network cable. Turning it off with the button is not enough, the spike jumps even across an off switch.
• If a surge has already hit, do not switch the device on repeatedly. If only part was damaged, further attempts can finish the job.
• If you smell burning or see smoke, leave the device off and unplugged. Do not reach inside and do not take risks, leave it to a professional.

What a surge usually destroys (and the good news)

Most often it takes out the power supply (PSU), which serves as the first line of defence and often sacrifices itself to protect the rest. Sometimes a surge damages the motherboard, the network card, or the router and modem if it came through a data cable.

The good news: the drive, and therefore your data, very often survives, even when the computer no longer starts. The damage tends to be in the power path, not in the stored files. So it pays not to rush and to have the device assessed.

Can the drive and data be saved?

• If the drive survived, the data can be read and copied to a new or repaired computer. We do this routinely, even when the rest of the device is a write-off.
• If the drive is also damaged, do not keep plugging it in and powering it up. Each further attempt can lower the chance of recovery. Hand it over for professional data recovery from a failed drive.

If you have a proper backup, a surge will not cost you your data even if the drive does not survive. That is the best insurance.

How to prevent further damage

We covered prevention in detail in UPS and surge protection. In short:

• Quality surge protection, not just any power strip “with protection”.
• A UPS backup unit for the computer, NAS and network devices. How to choose one is in how to choose a UPS.
• During a strong storm, unplug sensitive devices from both the socket and the network cable.

The surge damage may be reimbursed

If the surge came from the distribution grid (rather than a direct lightning strike on the house), the damage may be handled by the electricity supplier or your home insurance. Photograph the damaged devices, write it down and ask the service for a report that documents the cause and extent of the damage. With such evidence your claim has a much better chance.

Conclusion

A surge from a summer storm can destroy a computer even without a direct lightning strike, and the power supply is usually the first to go. The key is not to switch the device on repeatedly after a hit and to have it assessed, because the data on the drive often survives. For the future, surge protection, a UPS and unplugging during a storm all help. And when you have a backup, you are safe no matter what happens.

This article is part of the Repair and maintenance overview.