Lightning strike

keymoo · 1 Jul 2017 at 18:38

Last week there was a lightning strike right next to my house. Both my VDSL modem and my i7 PC got nuked. Both were plugged into a UPS so I'm confused as to why they weren't protected. Any ideas on this?

I've tried new power supplies on both but they're still dead. So, I've bought a new VDSL modem and that works fine, bigger problem is how to diagnose the server. Should I strip all the parts out and slowly add them in? Which order should I do that? I need to find out which parts work and which don't so I can replace them.

Thanks..

keymoo · 1 Jul 2017 at 18:54

I dunno, how do I find out? I bought in from overclockers back in 2012. It's this one: APC Back-UPS ES 700VA 230V UPS

keymoo · 1 Jul 2017 at 19:11

Thanks, from that page:

You must register the product by returning to APC the warranty card provided with the product within 10 days of purchase

I didn't do that. :-| Will look into a claim on home contents policy.

OK, next steps, how to diagnose the PC for damaged parts? I'm also considering replacing the UPS too as it seems defective, any recommendations?

keymoo · 2 Jul 2017 at 12:35

EsaT said:
It's things connected to both phone line and powerline which get often targeted by lightning... because both lines offer low resistance paths for surge to spread wider.

Though technically electric charge of lightning is always just following Ohm's law and looking for easiest path to ground.
It's just that voltage is so high that it can easily jump over airgaps and move through worser conductors to access better conductor.
Along with current of single strike even using multiple paths.
I was one of the guilties in feeding mosquitoes to get material for this:
https://www.researchgate.net/public...Trees_Preliminary_Statistical_Characteristics

Did you have any other electric devices broken or fuses blown?
That could narrow down primary source of surge.
If it came from phone line motherboard or at least NIC is common victim after modem. (and PSU can well be intact)
If from power line striking through PSU then probability for more destroyed components rises.

Only sure way to protect electric devices is to have surge or at least most of it diverted to ground before it can get to wiring inside the house.
Total energy of lightning strike can be up to hundreds of megajoules (dynamite in class of 5 MJ/kg) so should be easy to see why blocking even small part of that can be hard if that surge is already "knocking door" of that PC.
Hence it should be offered those paths toward ground as far as possible from device to be protected.
Ideally starting at that powerline before local transformer to low voltage.

Thanks for the great response. I've taken out the power supply and tried it in another PC and it spins up fine. When I put the power supply in the original PC it doesn't power up. I also tried a different power supply in the affected PC and it doesn't power up either. So, I guess the motherboard is fried in some way? Do you think I should order a new motherboard and swap it out? Do you think the CPU is fried as well? I don't have another motherboard with the same socket so I don't know.