PC Case Conducting Electricity

[alejandroPCM]

Hi all,

I have decided to start this thread because i ve been having the same problem with all of my builds and i cant seem to find any answers either on forums or on google.

MY CASE ZAPS ME!!!!

All 3 PCs i had in my house are zapping me! It all started with an old PC stuffed in a generic case with a generic power supply. I thought it was either the crappy case or the PSU not grounding.

When i built my current PC i used an AKASA Eclipse case with an Enermax Liberty 500W PSU. Same thing. I would get zapped anywhere i touched the case. And i m not refering to the USB ports (i know they have current ).

So i decided to change the case and went for the Antec P180 (excellent case) which is sound proof and has plastic around the side panels. I also powered it through an MGE Nova 600AVR UPS. NOTHING!!! the bloody thing stills zaps me!!

Anyone out there knows whats going on?

thnx

[pam123]

I had a customer move his computer from one room to another and in the new room it zapped anyone who touched it.
The problem turned out to be the carpet in the room that caused anyone walking across it to build up a personal static charge and then get zapped when they touched the computer.
I've also been told that those acrylic and metal office chairs can cause the same problem but I've never come across that myself.
Get one of those anti-static wrist straps,they're cheap, so you can ground yourself.
Turn on the computer, or do whatever usually gets you zapped, first without and then with, the wrist strap. Note what happens.
Move the computer to another socket, no carpeting and no wooly slippers, and try the same thing again.
If you're still getting zapped through it all then it's the computer.
If you only get zapped in the first room/socket but not the second call the electrician.
If you get zapped when your ungrounded but not when your grounded then you need to find a doorknob or something before you touch the computer.

[alejandroPCM]

thnx pam,

i can tell u the problem is not static! the pc rests on a marble floor and i m bearfoot.

Also, the current is constant. Static goes away after the first zap (discharges).

This is happening to all of my pcs. I can also tell u that every time i want to open the pc i have to unplug both the monitor to vga cable and the wire to the psu. Even after that there is still a slight current which can only be felt if you have slightly moist hands or if you touch the pc with the hair of your hands.

its really weird

[jamesrpm]

The outlet you are plugged into or it's circuit may be miswired. Hot/ neutral reversed it needs to be fixed as it is a hazard ! You can get a outlet checker for a few dollars at a hardware or building store.

[alejandroPCM]

i thought it might be the house wiring but thats why i got me a UPS to regulate and fix the power going to the pc.

guess its not enough...

[pam123]

If you "pull the plug" on a PC how long does it take till you can no longer feel the current?
The only time I've ever heard of this happening, I mean as a fault since power supplies take time to discharge the power they contain when they're disconnected, the house had an electrical problem.
I don't have time right now but I'll try later today to find that reference and you can see if it has anything you can use.

[alejandroPCM]

I know that a psu needs about 24 hrs to be safely discharged....i have never waited that long so i dont know if its that....but.....the psu is mounted on a bracket that has silicon padding...This would eliminate the psu leaking onto the case wouldnt it?

is it possible that the power is leaking through the metal bracket of the vga card? i cant beleive manufacturers are actually using metal parts without insulating them from the pcb!

[pam123]

I was forgetting. Here's how to drain a power supply.
To drain the capacitors in a computer power supply disconnect it from the wall socket and the monitor then hit the on button. The fans will spin up and the LEDs will light but it won't go on for long.
When it stops hit it again and wait.
You'll have to do this 4 or 5 times in a row till fans no longer spin and LEDs no longer light.
The power supply is now drained, and you shouldn't be able to feel any power at all.

edit : Okay found the answer.
I remebered this post from Toaster : http://forum.pcmech.com/showthread.php?t=52163
It's problem is that it's a shock hazard as well as fire hazard so you've got a real problem.

[flanzig1]

You don't want to isolate the PSU from the case. The metal contact between the case and the PSU is part of the ground plane for the whole computer system.