Van de Graaff Generator VS PC.

[Rob_D]

Hi guys,

 

Bit of an odd one. One of our science teachers has managed to kill his desktop with a van de graaff generator.

He was apparently running the generator on the desk (maybe half a meter away from the PC), and when he grounded the generator the PC "turned off" and now won't turn back on.

 

The motherboard lights show the PC's getting power and nothing looks physically damaged, but it won't turn on.

 

As far as I'm aware the PC being inside an earthed, metal box should protect it from this stuff like this.

So, is there anyone who knows more about this sort of thing who can postulate a theory as to what might have happened?

 

Thanks!

 

Edited to be about the device rather than the band.

Edited October 25, 2019 by Rob_D

[Davit2005]

So he earthed a Electrostatic generator to a PC?

 

Do you getting any beeps from the PC at all. I'm thinking motherboard damage but could be more, i the PC under warranty.

[robyholmes]

Swap the power supply and see if it just killed that. Also check your earth's in the room in question.

[Chris_Cook]

It'l be high voltage but low current won't it? Earthing might not be enough to protect it as the earth wire won't be zero ohms, just close to it - maybe 0.1 ohms. So there could still be a voltage difference between different points. There could also be EMP.

 

Daft question - did you check the monitor?

 

I'd check your getting all the voltages from the PSU. Could also try switching the CPU. Or completely disconnect the PC overnight and try again later.

[Andrew_C]

A VDG will be a broadband emitter. It could easy kill a PC with no connection between them at that distance. Equally, it could have killed the monitor.

[Sylv3r]

We've lost a PC or two over the years with a VDG Generator.

[Rob_D]

Thanks for the replies.

So he earthed a Electrostatic generator to a PC?

No he was sparking between the two domes of the generator (I'm sure there's a technical term for it)

 

The monitor appears fine (or at lest it comes on a says "no signal").

The Motherboard is getting power (board led comes on) so i think the PSU is good, dead board sounds most likely. No beeps, no fans, no nothing. PC's well out of warranty.

We've pretty much written off the PC, but want to get an idea of what happened so we can guard against it. I guess making them do the VDG demonstrations well away from the PC might be a good idea.

[Andrew_C]

I guess making them do the VDG demonstrations well away from the PC might be a good idea.

 

This^. Your only defence is the inverse square law. Double the distance ; 1/4 the power.

[msi_school]

I did this many years ago to a BBC Micro, the VDG was on the same desk as the Micro and the screen just went black and the Micro never came back. I had never thought about this but with my NM head on I dread to think what it cost to replace the computer.

[FishCustard]

A VDG will be a broadband emitter. It could easy kill a PC with no connection between them at that distance. Equally, it could have killed the monitor.

 

This is the issue. Voltage and grounding are irrelevant, you have a broad-band EMF emitter sitting near electronics. A big one can quite happily kill PCs and monitors.

 

Recommend doing it away from the PC! Preferably the other side of the room.