Electric current felt all over the case

[davemaster84]

Hi guys. I recently bought a thermalake element v nvidia edition case and I installed it myself, all runs very well except but the upper fan which wont change colors, but I think it's because I connected it to the board . Anyway the problem is that even when the pc is turned off (and the psu too) you can feel a low electric current running all across the case, I know it is not the board making a short circuit 'cause I used the pins so it is not touching the metal (if it has it would habe blown already ) but still it's kinda annoying. Could it be the metal plate that covers the board connectors (usb, scrteen etc)? Could it be the psu?

Thanks

 

[ahnilated]

You could try using a voltage meter and find out what the voltage is and that might help you nail down which area of the motherboard is grounding to the case.

 

[InvalidError]

If you can feel electricity on your case, it means your case is not properly grounded and something (probably the PSU or another line-powered device sharing a ground connection with the PC through cables) is leaking high voltage to the case.

Test your outlet's ground with an outlet tester or power bar with ground-fault indicator and test your equipment's ground connections with a multimeter by measuring resistance between the power cables' ground pin and equipment cases.

A properly grounded case should be unable to charge up to any sort of humanly detectable voltage.

 

[davemaster84]

It's a bit weird, it's gone for now. I've a metal desktop , would the case be properly grounded if I use a metal cord to attach the desktop to the case?

 

[InvalidError]

If your PC has bad ground and you connect it to your desk without connecting your desk to a proper ground, you risk electrocuting yourself by touching your desk if whatever was leaking current ends up making a hard connection to the live AC line.

Grounding should be tied as close to the source of a potential AC leak as possible. If you are going to hack a makeshift ground connection, it should be screwed to the computer case. Ideally though, you should investigate why your PC's ground did not work properly since it may reveal a more important yet silent wiring fault.

 

[clutchc]

First get an outlet tester and check your wall recept.
http://www.amazon.com/ELECTRICAL-RECEPTACLE-TESTER-OUTLET-PRONG/dp/B002Q3R7HI
You can probably find one at your local hdwr store.

If all is well, see if any of the I/O plate grounding/tension fingers are sticking into any of the ports on the back of the case. As far as the case sitting on a metal desk, it should be isolated from the desk by the case's non-conductive feet.

 

[InvalidError]

The highest voltage present in IO ports is 5V which would be difficult to detect unless you touched the PC with your tongue. For voltages to be felt with bare skin, it takes at least 30V which is much higher than any PSU output and can only come from a PSU's primary-side current leaking to an isolated ground.

Even if 5V could be sensed by touch, it does not change the fact that the case's potential should get shorted to ~0V by a proper connection to ground. Also, the case is connected to the PSU's local ground/0V through the PSU's case and motherboard mounting pads when using bronze studs so an IO plate finger touching 5V pins would short them out, making it impossible for IO ports to electrify the case with the PSU's own output voltages.

 

[davemaster84]

I can´t feel it anymore, and I didn´t feel it at the start, I know issues like this don´t go away alone, so I´ll keep both eyes on it. About the case´s grounding it is connected to an stabilizer which is connected to the wall´s 3 hole socket. I have never encountered this problem in my room before so I doubt it is the wall´s socket, but I think it could be something bad regarding the psu, it is a corsair hx850 silver, shouldn´t missbehave at all but if this continues I can always RMA it.

Thanks a lot

 

[InvalidError]

RMAing the PSU won't do you any good if you have a ground wiring problem in your walls, home/apartment, power bar/UPS, cables, etc.

If you have an intermittent (?) ground fault somewhere with equipment intermittently (?) leaking line power somewhere, you probably want to find it before a short to live injures someone... or possibly worse.

Right now, you do not know whether not feeling the current anymore is due to restored ground safely discharging the current leak or the faulty equipment not leaking current to the floating ground anymore.

 

[davemaster84]

Well I've an update here guys. I was just about to plug the hdmi cord from the card (gtx 680) to the splitter and then I saw sparks! The gpu appears to be ok but now I definetly blame the psu, can I remove it safetly to take it back to the store I bought it?

 

[InvalidError]

If you see sparks between the HDMI cable and the PC when both the PC and display should be connected to ground, it means your equipment is not properly grounded.

Your PC's PSU could be perfectly fine with the stray voltage actually coming from your display's PSU or other attached device and building up due to neither piece of equipment having a proper connection to ground.

If you "felt electricity" while the display was connected to the PC, it means neither your PC nor display had proper connection to ground at that time and this requires immediate attention regardless of whether or not either piece of hardware might be defective since they likely share a common cause as for why they have intermittent ground.

 

[davemaster84]

I'll call a technician right now to check my room's ground. I put the case together myself, could be that I made a bad connection somewhere? The only thing I recall doing new compared with all the previous times was adding the plate that goes right between the board and the case, where the connectors are attached, it fit perfectly but I don't recall seeing any plastic insolating the board from the case, could be that too?

 

[davemaster84]

Another thing I recall now is back when I had a gtx 460 sli, once I left my gf alone for the night and when I came back the hdmi port from the lower card was fried, same as for the hdmi port in the tv and my direct tv codifier almost died as well.

 

[InvalidError]

I put the case together myself, could be that I made a bad connection somewhere?

The PSU's power cable connects to the case ground through the PSU's case and/or PCB. The PSU's PCB connects to its case ground through its screw posts. The PSU's ground connects to your case through the screws that hold the PSU in your case. The PSU also connects to the motherboard's ground through GND wires and the motherboard also connects to case ground through the motherboard tray's mounting studs and screws.

Apart from the wire between the PSU's IEC socket and whatever it connects to, there are multiple ground paths within the PC/PSU case which makes it nearly impossible to NOT have a good ground connection due to wiring/assembly unless the ground wire within the PSU is not properly screwed/soldered/crimped. Highly unlikely but it can happen.

If you get a good power bar like an APC SurgeArrest, those have ground fault indicator LED. If you get one of those, plug it in and see the LED light up when you feel electricity, you'll know for certain you have bad site ground at least on that particular wall outlet.

 

[davemaster84]

After some light reading I saw that a lot of people have problems with HDMI connections, some as bad as damaged tv's, gpu's and all the combo. If after checking the switch ground it comes that's ok I think I'd rather not plug my hdmi into my tv again Anyway thanks for the help

 

[davemaster84]

Best answer selected by davemaster84.

 

[t0ms]

9 times out of 10 this is caused by people cheaping out on their electric cable.

People spend $1000s on a PC and then spend $2 on the electric cable that looks fine on the outside, but when you cut it open the metal wires are so hair thin the earth wire doesn't event get the job done. Some cheap cables are even made with junk metal mixed with a little copper and you can tell by the dark metal color.

Replace the cheap electric cable with a high quality one, don't try to save $5 and then have your house burned down. Respect electricity and get at least 1mm+ pure copper twin & earth, 0.75mm should be the bare minimum.

 

[dioyad]

My problem was a faulty power strip where my computer was plugged. The ground was disconnected (check the continuity between the grounds)