Hi!

I would really appreciate your help. The house where I live in was struck by a lightning - or more exactly, the WiFi aerial was hit. It has totally destroyed my router, my notebook (flames etc. - actually it was quite impressive ), but in my PC only the ethernet card's been damaged (runs at 10 Mbit now only). So I've got two issues to solve now:

1) How can I diagnose, if there's no other problem in my PC caused by the lightning? I use it for work mainly, so it's pretty important for me to make it work properly.
2) How can I protect my dear little LAN from such events? I've already bought some APC device, but it only protects from the overvoltage from the eletric outlet. Is there any way how to secure the WiFi line?

Thanks for replies and excuse my English please. I haven't spoken English for some time now.

There's virtually no way to 100% protect equipment if you suffer a direct lightning strike to connected equipment such as you described.

It probably goes without saying that the best defense is to unplug ALL external inputs (power and I/O) to every piece of equipment involved before the storm arrives. But sometimes, that isn't possible.

To help prevent direct strikes, you need an adequately designed and properly installed and maintained lightning-rod system.

Had the strike been on a nearby power-line or somewhere on the house...a surge/spike protector might have helped reduce the damage. There's no guarantee. However, some protectors come with a substantial equipment protection "guarantee" which may help in such cases to replace your damaged equipment. Be sure to read the fine print. There are usually very significant caveats and generally speaking...

...ALL sources of input to your equipment must be protected by the same company's equipment (power, internet, modem, display power, printers, etc.)

You should also know 2 additional things about surge/spike protectors:
The 1st thing is they "age". They may lose effectiveness over time assuming they are doing their job and helping prevent damaging disturbances from propagating to your system. The rate of degradation depends on the components used, the design, and the nature of the electrical disturbances. The 2nd thing is that if there is a proximate lightning strike, it is possible the protection provided by the devices has been at least partially and possibly completely compromised, and all of them should be replaced. Some protection devices have indicators when they should be replaced. However full replacement every few years provides superior protection. Obviously, that can get very expensive and most people prefer not to do that. Eventually, they may end up with a protector that is not much more than an over-sized extension power outlet. It all depends on the degree of risk you're willing to take.


As for diagnostics:
(note: even if a system passes diagnostics after a lightning strike, it remains possible that some damage caused by the strike may actually show symptoms only a long time after the event.)




edit-add lightning-rod comment
edit-latent damage comment
edit-highlight a key item and add the "2 additional things" paragraph for completeness

Thanks for Your reply!

Your post concerning the testing has been very helpful to me. I had already POSTed my PC before, now I am trying the tools you've mentioned. But could you be perhaps more specific about the WiFi line protection? I have already bougt some APC overvoltage protection with a power supply, but it only protects from the overvoltage from the eletric outlet. I haven't found any WiFi aerial or line protection yet. Also, I cannot do any reconstructions of the conductors or the house I live in , I've only hired it for some time.

I usually plug all the devices out, but I wasn't home and my friends thought having a LAN party during a storm would be great...

If you can't relocate your wi-fi then you have to have a lightning rod which is higher
than the wi-fi ariel. Lightning always strike the highest conductor. Hence why
churches/steeples always get hit.

OK. Let me specify, what I am asking for: I am looking for some overvoltage protection of the WiFi line. Except moving the aerial etc. what do you think would be the best thing to do? Is there perhaps some protection I could buy and place between the WiFi line and the router?

But anyways, thanks again for your replies. Thanks to John Albrich I have found out just now, that my MB has been damaged too... I am really sorry for that, because I gave 2 000 EURO for this PC half year ago.

Vojtech Kocman said:

You're welcome.

For antenna connection protection, your best resource is going to be Amateur Radio manuals and web-sites. LOTS of info out there from "Ham" operators with practical and economical approaches...and sometimes help with antenna and protection hardware camouflage ideas and methods. If the landlord is letting you put up an antenna, then he might not mind a protection hook-up. There are a few things you can do that will help reduce but not eliminate the problem with an exposed antenna.

You likely will remain limited by what you can do overall because of your lease situation, but you might talk with the landlord about it if lightning storms are a frequent problem. The landlord might be inclined to improve the property for his own benefit (reduce risk of property damage/fire, and may get insurance discounts...depends mostly on geographic area, I think).

You may also want to look into what renter's insurance can do.

there are surge protectors that also can protect your phone line and/or your LAN line

After a discussion with one electrician, I've bought and installed BrOK UPSKO N-f / N-m (35 USD) overvoltage WiFi protection. He of course told me that the protection won't help much against a direct lightning hit, but better than nothing anyways...

May the force be with you all

Vojtech,
Well that device may help but will not mitigate all damage to your systems.
A couple of things here.
1. If you have an external Wifi antenna attached to a Wifi router, AND the other systems damaged were connected WIRED to the WiFi router, then what you've seen would indicate an antenna based entrypoint.
2. If however, the laptop or other systems were NOT WIRED, but WiFi, then the strike actually traversed into your electrical system. This is more likely the source of FLAMES on your other system/s.
The Wifi arc-gap or other product would not protect the systems connected to your electricity. I would suggest several products by Panamax or APC that provide better isolation in Ethernet as well as electrical isolation, but none of them is actually perfect. In some cases though when you purchace the product you are also purchasing a insurance policy that will replace your HW in the event of a lightning strike or a massive surge.