Hi!

I'm having a problem here that's a bit scary. Often I get electricuted by
just touching the chassis of my computer. I've changed to a new PSU and a
new chassi, but it still happends no matter what combination I'm using.
Leaning over it to fix a cable behind it, just touching it and similar often
results in a bad chock, sometimes even so bad that it shortcuts the computer
and it goes black...
This CAN'T be good for the hardware (I know it's not good for me!).
Anyone have a clue where to start looking for a solution, what ahve I done
wrong in both machines that cause this? Is it related to the PSU, the case,
the motherboard, what??

Best Wishes
Thomas

sounds like a bad ground,

"Thomas Andersson" <(E-Mail Removed)> wrote in message
news:bgatmp$lug0u$(E-Mail Removed)...
> Hi!
>
> I'm having a problem here that's a bit scary. Often I get electricuted by
> just touching the chassis of my computer. I've changed to a new PSU and a
> new chassi, but it still happends no matter what combination I'm using.
> Leaning over it to fix a cable behind it, just touching it and similar
often
> results in a bad chock, sometimes even so bad that it shortcuts the
computer
> and it goes black...
> This CAN'T be good for the hardware (I know it's not good for me!).
> Anyone have a clue where to start looking for a solution, what ahve I done
> wrong in both machines that cause this? Is it related to the PSU, the
case,
> the motherboard, what??
>
> Best Wishes
> Thomas
>
>
>

Thomas-

This could be caused by some peripheral equiptment as well. Disconnect all
AC powered peripherals from the computer (Peinter, Speakers, Monitor etc.)
Test to see if the problem is gone. If it is, check the power cords and
reconnect the items one at a time until the problem comes back. If not,
Check/replace the power cord for the computer and Check the wiring of the
outlet that it plugs into. It is possible that the outlet is wired backwards
(Swapping the hot & neutral lines - hmm - this is actually the most likely
cause now that I think about it.)

To test, use a volt meter aet for AC to check for voltage between the case
and a known ground. It should read 0. If it reads 110V - 120v then the
ground to the computer is actually Hot.

Hope this helps.

-Xathros

"Thomas Andersson" <(E-Mail Removed)> wrote in message
news:bgatmp$lug0u$(E-Mail Removed)...
> Hi!
>
> I'm having a problem here that's a bit scary. Often I get electricuted by
> just touching the chassis of my computer. I've changed to a new PSU and a
> new chassi, but it still happends no matter what combination I'm using.
> Leaning over it to fix a cable behind it, just touching it and similar
often
> results in a bad chock, sometimes even so bad that it shortcuts the
computer
> and it goes black...
> This CAN'T be good for the hardware (I know it's not good for me!).
> Anyone have a clue where to start looking for a solution, what ahve I done
> wrong in both machines that cause this? Is it related to the PSU, the
case,
> the motherboard, what??
>
> Best Wishes
> Thomas
>
>
>

I had a nice long reply typed out then changed my mind as to what advice to
offer..
You posted from a berlin server so I am assuming your on the same 240v
system that we are on here in the UK..
I would test to see how much voltage is coming through the case (test it
with the pc power off).. The problem that we have with our supplys is that
sometimes the earth and neutral will will float apart (yes they do**).. so I
would test the case to a known good ground.. like a metal waterpipe or
something similar.. You could even just test and see if it's wired
correctly.. This is what I would do "last" after checking to see that there
are no skint wires or anything else inside your case.. But if you have a DVM
it's going to be dead easy to just check the Earth&Neutral

(**yes they do)
I have caught mine "floating" by about 11 volts, a check just now shows it's
rock steady.. But maybee I connected the E&N when I replaced my ConsumerUnit
(Breaker Box)..

"Thomas Andersson" <(E-Mail Removed)> wrote in message
news:bgatmp$lug0u$(E-Mail Removed)...
> Hi!
>
> I'm having a problem here that's a bit scary. Often I get electricuted by
> just touching the chassis of my computer. I've changed to a new PSU and a
> new chassi, but it still happends no matter what combination I'm using.
> Leaning over it to fix a cable behind it, just touching it and similar
often
> results in a bad chock, sometimes even so bad that it shortcuts the
computer
> and it goes black...
> This CAN'T be good for the hardware (I know it's not good for me!).
> Anyone have a clue where to start looking for a solution, what ahve I done
> wrong in both machines that cause this? Is it related to the PSU, the
case,
> the motherboard, what??
>
> Best Wishes
> Thomas
>
>
>

Check the power input cable. When you usually get shocked like that, the
ground pin is open in the power cable or the wall socket.

"HVsucks|[PSY-W]ThrasherK" <(E-Mail Removed)> wrote in message
news:G98Wa.53475$(E-Mail Removed)...
> *clapclapclap* nice work
>
> Heh, sorry, I had to. Anyways to try and help fix:the problem:
>
> 1) If you're not getting zapped hard enough to hurt, then you're getting a
> 5V or 12V tickle from inside of your case. You'd know for sure if it was
a
> 120V blast you got (not to mention your computer would be 100% fried)
>
> 2) Pull the PSU from the case, but leave everything else plugged into
it.Set
> the PSU down on a book or something similar, turn the system on. See if
its
> the PSU zapping you or if its something inside the case. If its the PSU,
> buy a new one (Antec/Enermax or similar) if its inside the case continue:
>
> 3) Remove the PSU wires from inside the tower, and examine all of them
> closely. if any are exposed tape em up well, or replace the PSU one of
the
> two.
>
> 4) If none of its the PSU, get someone who knows what they're doing to
help
> you disassemble and reassemble the entire case, as something in your
> hardware is directing power straight to the chassis.
>
>
>
> --
> Mike ''Thrasher'' Kitchenman
> Don't ask, you probably don't want to know.
> (And if you figure it out, hell I'd be interested in hearing.)
> "Thomas Andersson" <(E-Mail Removed)> wrote in message
> news:bgatmp$lug0u$(E-Mail Removed)...
> > Hi!
> >
> > I'm having a problem here that's a bit scary. Often I get electricuted
by
> > just touching the chassis of my computer. I've changed to a new PSU and
a
> > new chassi, but it still happends no matter what combination I'm using.
> > Leaning over it to fix a cable behind it, just touching it and similar
> often
> > results in a bad chock, sometimes even so bad that it shortcuts the
> computer
> > and it goes black...
> > This CAN'T be good for the hardware (I know it's not good for me!).
> > Anyone have a clue where to start looking for a solution, what ahve I
done
> > wrong in both machines that cause this? Is it related to the PSU, the
> case,
> > the motherboard, what??
> >
> > Best Wishes
> > Thomas
> >
> >
> >
>
>

HVsucks|[PSY-W]ThrasherK wrote:

> 1) If you're not getting zapped hard enough to hurt, then you're
> getting a 5V or 12V tickle from inside of your case. You'd know for
> sure if it was a 120V blast you got (not to mention your computer
> would be 100% fried)

Maybe not lethal, but painfull enough :/

> 2) Pull the PSU from the case, but leave everything else plugged into
> it.Set the PSU down on a book or something similar, turn the system
> on. See if its the PSU zapping you or if its something inside the
> case. If its the PSU, buy a new one (Antec/Enermax or similar) if
> its inside the case continue:

As I said it happends with both my new and old system, or any combination of
them. The old one uses a noname 250W PSU and the new one a brand new Enermax
420W PSU.

> 3) Remove the PSU wires from inside the tower, and examine all of them
> closely. if any are exposed tape em up well, or replace the PSU one
> of the two.

All cables apear to be OK from what I can tell (except one on the old PSU
which I have taped up already).

> 4) If none of its the PSU, get someone who knows what they're doing
> to help you disassemble and reassemble the entire case, as something
> in your hardware is directing power straight to the chassis.

Gonna experiment some toay and see if I can find out additional info about
the problem!

Best Wishes
Thomas

johnnie7 wrote:

>> I'm having a problem here that's a bit scary. Often I get
>> electricuted by just touching the chassis of my computer. I've
>> changed to a new PSU and a new chassi, but it still happends no
>> matter what combination I'm using. Leaning over it to fix a cable
>> behind it, just touching it and similar often
>> results in a bad chock, sometimes even so bad that it shortcuts the
>> computer and it goes black...
>> This CAN'T be good for the hardware (I know it's not good for me!).
>> Anyone have a clue where to start looking for a solution, what
>> ahve I done
>> wrong in both machines that cause this? Is it related to the PSU,
>> the case, the motherboard, what??

> have you got a scanner conected to your pc?

Nope, external connections are ethernet to a ADSL modem, VGA cable to
monitor and line in/out to my stereo amp.

Best Wishes
Thomas

have you got a scanner conected to your pc?


john






"Roger" <(E-Mail Removed)> wrote in message
news:1jbWa.51152$zy.23767@fed1read06...
>
>
> spodosaurus wrote:
> > Thomas Andersson wrote:
> >
> >> Hi!
> >>
> >> I'm having a problem here that's a bit scary. Often I get electricuted
by
> >> just touching the chassis of my computer. I've changed to a new PSU and
a
> >> new chassi, but it still happends no matter what combination I'm using.
> >> Leaning over it to fix a cable behind it, just touching it and similar
> >> often
> >> results in a bad chock, sometimes even so bad that it shortcuts the
> >> computer
> >> and it goes black...
> >> This CAN'T be good for the hardware (I know it's not good for me!).
> >> Anyone have a clue where to start looking for a solution, what ahve I
> >> done
> >> wrong in both machines that cause this? Is it related to the PSU, the
> >> case,
> >> the motherboard, what??
> >>
> >> Best Wishes
> >> Thomas
> >>
> >>
> >>
> >
> > You might want to post this to
> > alt.comp.hardware.pc-homebuilt...nevermind, I'll do that now...
> >
> > You have a short somewhere in there. If the motherboard and components
> > are not already fried (I'd bet they've already sustained damage) then
> > I'd suspect the short is in the power supply itself, or you've managed
> > to damage a wire coming out from the power supply and this is contacting
> > the case. Either way, don't use the computer anymore until this is
fixed.
> >
>
> I am not an engineer, so there is probably better advice elsewhere. But
> I think an outright short would fry something.
>
> One possibility is you are charged up, not your PC case, and you should
> be able to duplicate the static shock by touching the screw on a nearby
> outlet cover.
>
> The other possibility is your case is charged up because it is not
> properly grounded. Somewhere there should be an electrical contact (just
> metal to metal) between the neutral wire on your power cord, the power
> supply, and the case. This contact should drain off any static charges
> caused by spinning fans, etc.
>
> In the unlikely event you have two problems, both a grounding problem
> and a wire short, fixing only the gounding problem should cause
> something to fry, hopefully not yourself.
>
> Roger
>

Perhaps there is no ground at the outlet, i.e. no connection between the
ground pin and the real ground.

-=-
Alan


On 07/31/03 12:13 pm Thomas Andersson put fingers to keyboard and
launched the following message into cyberspace:

> Hmm, but as I said this occurs in both my brand new system as well as my old
> one, or any combination of the two (cables, PSU etc). I'm gonna experiment
> with all external cables today and see if any single one is the culprit.

Hi, you first need to check that your 3rd wire ground lead from the wall
plug is actually connected to earth ground, such as a cold water pipe.
There are testing devices you can buy to find out, or call an electrician.
If you do have a floating ground, this is a potentially lethal problem that
must be fixed ASAP.

BTW, a good quality UPS device should have an internal transformer that will
prevent this sort of problem. I believe they use transformers, not certain
tho.

rms

"Thomas Andersson" <(E-Mail Removed)> wrote in message
news:bgatmp$lug0u$(E-Mail Removed)...
> Hi!
>
> I'm having a problem here that's a bit scary. Often I get electricuted by
> just touching the chassis of my computer. I've changed to a new PSU and a
> new chassi, but it still happends no matter what combination I'm using.
> Leaning over it to fix a cable behind it, just touching it and similar
often
> results in a bad chock, sometimes even so bad that it shortcuts the
computer
> and it goes black...
> This CAN'T be good for the hardware (I know it's not good for me!).
> Anyone have a clue where to start looking for a solution, what ahve I done
> wrong in both machines that cause this? Is it related to the PSU, the
case,
> the motherboard, what??
>
> Best Wishes
> Thomas
>
>
>