Grounding issue

[alphakry]

Well, i have been having an odd issue with my PSU - so i'm wondering if anyone here has experienced this...

the details were actually originally posted in the following thread:
http://www.hardforum.com/showthread.php?t=960189

When I touch certain parts of my case - a slight shock is felt.

It is best tested for by sticking my tounge to the case - quite like a 9v battery.
I notice that on parts where there is a small scratch, and the bare aluminum showing - there is a tingle.

I have tested a few places - including screws on my radiator, the mobo tray and the screws holding in the hdd... all of them have this "charge" ... and it's alarming.

The charge still exists when I unplug the power from the psu... it felt a bit fainter but it still existed.

So to further focus on the possible cause, I was wondering if this sounds like a PSU problem? I have checked all the wires and none of them are exposed or touching anything they shouldn’t.

 

[davidhammock200]

Probably not a PSU issue, a wall socket issue it is.

 

[alphakry]

david... but after being powered down and unplugged for over 12 hours - how could it be the wall socket?

 

[davidhammock200]

david... but after being powered down and unplugged for over 12 hours - how could it be the wall socket?

It is unplugged & sitting on a non-conductive surface & it still shocks you???

 

[alphakry]

yessir! quite odd indeed.... i am getting a Fluke tommorrow to test an actual read... but this is indeed true - there is still the tingle after being unplugged for over 12hrs...

which leads me to believe some type of transistor, be it in the psu or mobo, is keeping a current.

 

[alphakry]

is it possible that because I painted the entire case (minus the external panels and the mobo tray) with Dupli-Color Mirage paint - effective grounding has been lost?

The case isn't the best out there - a simple Aspire X-Dreamer

This [H] thread got me thinking.

I got my hands on a Fluke - so i will post numbers tonight to determine if the amounts noticed are dangerous.. Any specific tests i should make sure i do?

 

[larrymoencurly]

I used to think that all PSUs contained bleeder resistors to discharge their big capacitors in about 20 minutes (if the standby +5V supply doesn't drain them in 20 seconds), but I learned that this isn't true, and not just for cheapos but even some major brands, like Enermax. On a few occasions I've pressed the front panel power button on my Enermax-equipped computer without first turning on the power strip, which had been turned off for hours, and I could hear the fans spin for a fraction of a second.

If you leave the power cord plugged in and turn off the switch on the rear or the switch on the power strip, do you still feel voltage on the case? Because if you do, then your wall AC outlet isn't grounded.

 

[alphakry]

I used to think that all PSUs contained bleeder resistors to discharge their big capacitors in about 20 minutes (if the standby +5V supply doesn't drain them in 20 seconds), but I learned that this isn't true, and not just for cheapos but even some major brands, like Enermax. On a few occasions I've pressed the front panel power button on my Enermax-equipped computer without first turning on the power strip, which had been turned off for hours, and I could hear the fans spin for a fraction of a second.

If you leave the power cord plugged in and turn off the switch on the rear or the switch on the power strip, do you still feel voltage on the case? Because if you do, then your wall AC outlet isn't grounded.

i think i did something more extreme then that - leaving the PSU unplugged from the wall for 12hours - so that there was no wires whatsoever going to the PC itself... and the charge was still there. But for arguments sake, i'll try what you suggested.

 

[alphakry]

totally odd... all of a sudden, it is gone...

i tested my outlets - in both the wall and Energizer UPS unit that i plug into.

All had a Ground+Hot of 118.5 V~ and a Ground+Neutral of about 1.1V~.

I went to go test the PC and sure enough, i don't feel the charge anymore and the fluke shows a 0.00 number of Ground+PC... it just got up and went away! how frustrating....