A Shocking Discovery

[Gerowen]

We have a desktop PC connected to our living room TV. Twice now I've had my shoes still on and built up enough static that when I touched it there was a loud pop and the machine powered off. After which the computer will power on but i get no POST beep, no video output, nothing. It apparently does something to corrupt the BIOS saved data because the only fix is to pop the CMOS battery or short the reset pins to hard reset the UEFI and then go put all my settings back in.

This morning I was just removing a Bluray from the optical drive from yesterday. When my fingers approached the metal of the case I got a strong zap and it turned off, and I had to reset the BIOS.

This only happens if I'm wearing shoes. The room has carpet. The computer is connected to an UPS. I'm guessing since the machine is grounded to the wall outlet the static buildup sees the computer case as the shortest path to earth and it's a strong enough arc to mess with the UEFI. Also, for some reason it wouldn't recognize the internal drive as bootable until I used refind to boot the machine and reinstalled the bootloader.

 

Something about the path that static takes really makes the system unhappy. Have to remember not to touch it if I'm wearing shoes.

[TatamiMatt]

8 minutes ago, Gerowen said:

We have a desktop PC connected to our living room TV. Twice now I've had my shoes still on and built up enough static that when I touched it there was a loud pop and the machine powered off. After which the computer will power on but i get no POST beep, no video output, nothing. It apparently does something to corrupt the BIOS saved data because the only fix is to pop the CMOS battery or short the reset pins to hard reset the UEFI and then go put all my settings back in.

This morning I was just removing a Bluray from the optical drive from yesterday. When my fingers approached the metal of the case I got a strong zap and it turned off, and I had to reset the BIOS.

This only happens if I'm wearing shoes. The room has carpet. The computer is connected to an UPS. I'm guessing since the machine is grounded to the wall outlet the static buildup sees the computer case as the shortest path to earth and it's a strong enough arc to mess with the UEFI. Also, for some reason it wouldn't recognize the internal drive as bootable until I used refind to boot the machine and reinstalled the bootloader.

 

Something about the path that static takes really makes the system unhappy. Have to remember not to touch it if I'm wearing shoes.

You could try grounding your case so the shock bypasses components, runs through the cases metal and straight into ground, should stop any power offs or static shocks/surges through the components, might still cause shocks but shouldnt be harmful to the system anymore

[Mark Kaine]

22 minutes ago, Gerowen said:

We have a desktop PC connected to our living room TV. Twice now I've had my shoes still on and built up enough static that when I touched it there was a loud pop and the machine powered off. After which the computer will power on but i get no POST beep, no video output, nothing. It apparently does something to corrupt the BIOS saved data because the only fix is to pop the CMOS battery or short the reset pins to hard reset the UEFI and then go put all my settings back in.

This morning I was just removing a Bluray from the optical drive from yesterday. When my fingers approached the metal of the case I got a strong zap and it turned off, and I had to reset the BIOS.

This only happens if I'm wearing shoes. The room has carpet. The computer is connected to an UPS. I'm guessing since the machine is grounded to the wall outlet the static buildup sees the computer case as the shortest path to earth and it's a strong enough arc to mess with the UEFI. Also, for some reason it wouldn't recognize the internal drive as bootable until I used refind to boot the machine and reinstalled the bootloader.

 

Something about the path that static takes really makes the system unhappy. Have to remember not to touch it if I'm wearing shoes.

this basically means your case isn't grounded properly, which can have many reasons,  like cheap usb cables etc. 

[OddOod]

The case should be grounded through the power outlet and thus bypass all PC components. Path of travel should be you > case > PSU shell > ground wire in power cable > third prong (in some sockets or other grounding point in socket) > house wiring > ground stake outside
My suspicion would be either a terrible PSU or faulty house wiring. Do you live in an OLD building or one where someone has done a lot of DIY?

[Gerowen]

4 hours ago, OddOod said:

The case should be grounded through the power outlet and thus bypass all PC components. Path of travel should be you > case > PSU shell > ground wire in power cable > third prong (in some sockets or other grounding point in socket) > house wiring > ground stake outside
My suspicion would be either a terrible PSU or faulty house wiring. Do you live in an OLD building or one where someone has done a lot of DIY?

Negative; the house is new-ish (was built for us) and I drove and connected the ground rods myself. It could be the power supply I guess; it's a Thermaltake 650 watt unit. I could also go check the ground rods to make sure they haven't corroded or anything.

[TetraSky]

I would suggest using a multimeter to check the conductivity between the ground prong on the back of the PSU and the case (unpainted surface). It should show 0.0Ω.

If it does not, it means all the static goes straight into your components.

 

It it is not 0.0Ω, see if the ground prong of the PSU and the metal casing of the PSU is 0.0Ω. Because if it is not... That's a big problem. If it is, simply screwing the PSU in the case should create the pathway for conductivity between the two. Could be possible that there's too much paint and it's blocking it off...

Electricity goes in the path of least resistance. If the ground is properly connected, it should almost never affect your components.

 

After that the ground rod could possibly be at fault if it was not properly installed. You mentioned having done it yourself... On a new construction ? Shouldn't it have been done by default by the construction company or an electrician when they installed your panel ?

 

 

 It is also possible that you have an extra standoff installed in the case behind the motherboard, which creates a contact point where it really shouldn't have any.

[Gerowen]

On 8/13/2024 at 8:36 PM, TetraSky said:

I would suggest using a multimeter to check the conductivity between the ground prong on the back of the PSU and the case (unpainted surface). It should show 0.0Ω.

If it does not, it means all the static goes straight into your components.

 

It it is not 0.0Ω, see if the ground prong of the PSU and the metal casing of the PSU is 0.0Ω. Because if it is not... That's a big problem. If it is, simply screwing the PSU in the case should create the pathway for conductivity between the two. Could be possible that there's too much paint and it's blocking it off...

Electricity goes in the path of least resistance. If the ground is properly connected, it should almost never affect your components.

 

After that the ground rod could possibly be at fault if it was not properly installed. You mentioned having done it yourself... On a new construction ? Shouldn't it have been done by default by the construction company or an electrician when they installed your panel ?

 

 

 It is also possible that you have an extra standoff installed in the case behind the motherboard, which creates a contact point where it really shouldn't have any.

I had an electrician on hand to help me get it all taken care off so I could get it done and then sign off on it once it was finished.  Multiple grounding rods spaced a certain distance apart, etc.  I can go double check on them though to make sure there hasn't been excess corrosion or anything build up between the clamps and the rods themselves.

 

It could be the paint on the case.  The power supply is screwed it, but both it and the case are painted, and the screws are black though I'm not sure if that's paint or some other kind of coating.

 

I'm not sure if it's related to the electricity though; I went walking across the living room with shoes on to go to work the other day and when I touched the metal handle on my screen door it shocked the daylights out of me.

 

But it only ever happens if I have my tennis shoes on and have been walking around on the carpet for a few minutes.

[Soid]

18 minutes ago, Gerowen said:

I had an electrician on hand to help me get it all taken care off so I could get it done and then sign off on it once it was finished.  Multiple grounding rods spaced a certain distance apart, etc.  I can go double check on them though to make sure there hasn't been excess corrosion or anything build up between the clamps and the rods themselves.

 

It could be the paint on the case.  The power supply is screwed it, but both it and the case are painted, and the screws are black though I'm not sure if that's paint or some other kind of coating.

 

I'm not sure if it's related to the electricity though; I went walking across the living room with shoes on to go to work the other day and when I touched the metal handle on my screen door it shocked the daylights out of me.

 

But it only ever happens if I have my tennis shoes on and have been walking around on the carpet for a few minutes.

 

Start at the plug itself. Could be the wire came loose. You can buy a basic plug tester for about $10, and it'll tell you if it's wired correctly and grounded.