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ToggleHead
TWEAKGURU
Joined: 03 Mar 2004
Posts: 4360
Location: Jersey
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 Posted: Sun Aug 29, 2004 4:10 pm Post subject: getting zapped by my case... |
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ok still getting zapped now........where should i look for these problems.......its NOT in the woring.....what about mobo stands.........anyone tell me where to look?
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| Posted: Sun Aug 29, 2004 4:10 pm Post subject: Advertisement |
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Ham_fisT
Lord of the Tweak
Joined: 20 Jun 2004
Posts: 2244
Location: Gone Fishin'
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| Posted: Sun Aug 29, 2004 4:20 pm Post subject: |
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check the Ground at the A/C outlet
is there an external ground wire on the PSU?
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ToggleHead
TWEAKGURU
Joined: 03 Mar 2004
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Location: Jersey
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| Posted: Sun Aug 29, 2004 4:28 pm Post subject: |
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no external ground....all the house grounds are good.....big ass cables and an apc........i think its a case thing.........any place i should check...or similar experiances?
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Ham_fisT
Lord of the Tweak
Joined: 20 Jun 2004
Posts: 2244
Location: Gone Fishin'
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| Posted: Sun Aug 29, 2004 4:29 pm Post subject: |
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and this is a different PSU than the one that was shocking you before?
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2old2care
Lord of the Tweak
Joined: 09 Jul 2004
Posts: 2817
Location: Pssst....Over Here
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| Posted: Sun Aug 29, 2004 4:34 pm Post subject: |
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Question your UPS.
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Liquid-Cooled Q9450 and an EeePC
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Yoshida
UberTweaker
Joined: 24 Dec 2003
Posts: 1219
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| Posted: Sun Aug 29, 2004 4:39 pm Post subject: |
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sometimes it feels like im getting zapped when i touch my pc but i think its just a spasm in my hand :/
simple solution, wear rubber gloves whenever you need to touch your pc.
my only real suggestion is to check EVERYTHING gut your pc if you have to,
where is your pc? desk? floor? what kinda case is it? |
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Silicon Skum
UberTweaker
Joined: 26 Jul 2004
Posts: 1156
Location: UK, Geordie land
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| Posted: Sun Aug 29, 2004 7:49 pm Post subject: |
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Simple answer is yes you are getting an electric shock, No I do'nt know what is causeing it or how to fix it, mainly for two reasons
1) I have the same problem on my server (5 years I've put up with it) 
2) I'm actually very drunk right now (lock in at the pub YAY!) 
I think it has somthing to do with switching power suplys, I figre it out tomorrow and do something somthing......... too drunk / tired right now,
Ss |
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ToggleHead
TWEAKGURU
Joined: 03 Mar 2004
Posts: 4360
Location: Jersey
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| Posted: Sun Aug 29, 2004 8:27 pm Post subject: |
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HA HA...youre getting like me......lol
i knew i was getting shocked.....but its not cuz of the psu...it did it with the one before this one too......and the first but noe this bad.....lol
only when i touch certain parts of case.......maybe mobo remount.....?
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JayDubya
TWEAKGURU
Joined: 01 Oct 2003
Posts: 5496
Location: ames, ia
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| Posted: Sun Aug 29, 2004 9:18 pm Post subject: |
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Make sure the motherboard is on standoffs. Try and put small rubber washers on these standoffs on both the top and bottom of the motherboard(with the computer off). I would also try a new cable going to your power supply. This most definately sounds like a grounding issue.
Do you have a multimeter? IF so, test for voltage. Start at a 200v level and if it doesn't read much, move down to 20v or whatever your steppings are. You will need to put the two leads of the multimeter on any two parts of bare metal on the case. Report the voltage seen.
I'm glad I'm not the only drunk right now 
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Scoth
SirTweaksabit
Joined: 23 Feb 2004
Posts: 283
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| Posted: Sun Aug 29, 2004 9:26 pm Post subject: |
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| look on the bright side... you have a little anti-theft device on your computer :-D no one touch! |
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ToggleHead
TWEAKGURU
Joined: 03 Mar 2004
Posts: 4360
Location: Jersey
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| Posted: Sun Aug 29, 2004 9:43 pm Post subject: |
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GOOD call scoth.....=].....maybe i wont fix it but I'LL AMPLIFY IT!!!!!!!
heh heh.......but thats a good idea JW.......i'll let you know
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Silicon Skum
UberTweaker
Joined: 26 Jul 2004
Posts: 1156
Location: UK, Geordie land
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| Posted: Mon Aug 30, 2004 9:20 am Post subject: |
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| Silicon Skum wrote: | Simple answer is yes you are getting an electric shock, No I do'nt know what is causeing it or how to fix it, mainly for two reasons
1) I have the same problem on my server (5 years I've put up with it)
2) I'm actually very drunk right now (lock in at the pub YAY!)
I think it has somthing to do with switching power suplys, I figre it out tomorrow and do something somthing......... too drunk / tired right now,
Ss |
Ya know, I don't remember posting this!  man I was wasted last night!
Anyways, there is a strange side effect of a switching PSU, it can generate and add a floating voltage, somtimes it is picked up by the case from the ground lines, or more likely the case NEEDS grounding to the PSU ground line as it is not grounded and the MOBO is feeding a floating voltage from the PSU via the + voltage lines. Dont ask me how or why this happens, I'm not that hot with switch mode PSU design, I only know that I have sucessfully run a laptop via a switched PSU using only ONE single + feed wire and NO GROUND connections!
I'm not 100% sure about this but I think that the floating voltage is an ac or at a high frequency pulsing dc. it's low current, just stings a bit.
You will mainly notice it if you have some other devices with their own PSU and you touch the case and hold the connector in your hand (hurts like hell). What else do you have connected to your system?
Printers, some scanners, even monitors can generate / amplify this.
Simple test; unplug EVERYTHING from the case and power it up, do you get a shock? if not then it's not the computer PSU, add things one at a time until you get a shock and you have an answer.
I've got a a 10Mb hub when connected to the server and the older machines (10Mb coax - BNC) the end terminator can generate several hundred volts, I have to ground this to an eath point on the mains or I get a nasty suprise every time I accidentally touch it
Try connecting a grounding wire from your case to a water pipe, it should solve the problem. (though my server PSU is grounded (british 3 core mains) and the case still has voltage)
BTW this voltage can trip power breakers (RCD) in the mains supply.
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ToggleHead
TWEAKGURU
Joined: 03 Mar 2004
Posts: 4360
Location: Jersey
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| Posted: Mon Aug 30, 2004 9:59 am Post subject: |
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no i KNOW its compy.....nothing odd connected...and it does it with nothing else plugged in........i KNOW i mounted the mobo right........and everything else as well......now yesterday i noticed my side panel intake fan was off........i figured it shorted and blew......so when i went to swap it out and i took the door off.....it went on again.......hmmm THIS is when i noticed the bad shock.....
Most parts of the case, back panel etc.....have just that little tingly vibration current........but SOME parts......if touched with the right part of skin, (e.g. fore arm, back of hand etc..)......ZAPS me......not too bad.....just a stinger......should i ground the psu to the case.....or ground the case to a house ground?
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2old2care
Lord of the Tweak
Joined: 09 Jul 2004
Posts: 2817
Location: Pssst....Over Here
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| Posted: Mon Aug 30, 2004 10:43 am Post subject: |
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I was just assuming this PSU is screwed to the case metal to metal. That assumption made...Have you tried replacing the power cord? I know... here we go with the obvious again.
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JayDubya
TWEAKGURU
Joined: 01 Oct 2003
Posts: 5496
Location: ames, ia
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| Posted: Mon Aug 30, 2004 10:51 am Post subject: |
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| Silicon Skum wrote: | << You were drunk. One lower case s
it can generate and add a floating voltage, somtimes it is picked up by the case from the ground lines
SS |
Are you talking an induced voltage? Induced voltages require either moving charge or moving metal through a magnetic field. How possible would it be that a moving charge somewhere is inducing a voltage on the case?
I would definately try replacing the power cord first. IF that doesn't work, then try finding a nice peice of bare metal on the case and a nice piece of bare metal on the psu to make your ground (preferably on the psu ground that is already there). Make sure you have the shortest wire possible. 10-16 gauge should be plenty.
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PhRoZeN_X_
SirTweaksabit
Joined: 19 Jun 2004
Posts: 410
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| Posted: Mon Aug 30, 2004 10:53 am Post subject: |
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For your saftey and your PC's just try swapping out your power supply, I am studing to become an electrican and the simplest answer is usualy the right one. If that doesn't help or fix it try to create your own ground from the power supply. Or try this
1) where you mobo is screwed on with thoes rubber mounts , take one off
2)get a piece of copper wire
3) sand a little of the finish off your case ( where no one can see)
4) wrap the copper wire around the screw ( still use rubber mount)
5) connect the wire from your mobo to your case , then atleast your mobo is grounded.
Also most of the cases i have seen have little legs on the bottom( they are rubber) this should prevent your case from zapping you.
One more thing , if you have an older home with old wiring it may have nothing to do with your computer. If its a fuse box or you have several things plugged into your wall socket, than you may actualy be getting little power surges to your pc. These surges may not be enough to hurt you pc but it MAY be enough to be givig off static charges or electric currents.
Try taking your pc to antoher room in the house ( try another floor if posible) and plug it in there and see if it makes a difference.
Oh and one final thing ,my buddy had a similar problem and it was his monitior. It had a faulty cord and was sending the current threw his video card and where his video card was screwed on to the outside of the case it wasn't grounded properly and "ZAP" that is where his problem was |
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ToggleHead
TWEAKGURU
Joined: 03 Mar 2004
Posts: 4360
Location: Jersey
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| Posted: Mon Aug 30, 2004 12:34 pm Post subject: |
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interesting....i'll check the monitor thing....but as i said, this happened when JUST the comp was plugged in....no nothing else.........i KNOW the PSU is fine....im sure weazel didnt have these problems.....=P
i have NOT checked the power cord......didnt even think of it........i'll do that tonight.......i'll the grounding later too if taht doesnt work.....
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Silicon Skum
UberTweaker
Joined: 26 Jul 2004
Posts: 1156
Location: UK, Geordie land
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| Posted: Mon Aug 30, 2004 1:35 pm Post subject: |
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[quote="JayDubya"] | Silicon Skum wrote: | << You were drunk. One lower case s
it can generate and add a floating voltage, somtimes it is picked up by the case from the ground lines
SS |
Are you talking an induced voltage? Induced voltages require either moving charge or moving metal through a magnetic field. How possible would it be that a moving charge somewhere is inducing a voltage on the case?
quote]
I use the term "floating" for lack of a better one. The voltage SEEMS and acts like a floating (open circuit) voltage, little current and no direct connection to a supply. Also the voltage can be quite high, I measured about 150V on my server case, yet this bears NO relation to ANY of the voltages either produced by or used by the PSU (I'm on a 250V mains, so it's not a short or fault)
As for what could generate it in a PSU, well have a look in there, it has plenty. A bad design with the voltage regulators / switching could cause it. Also a "ringing" transistor can induce an electrical voltage in nearby circuits. take the tube out of a battery powered flurecent tube light and you can actually hear the high frequency "Ringing" of the transistor (will damage it though).
TH, ground the case to a water pipe (this is what the earth usually is in house electrical systems) Be carefull if the MAINS has a ground, it could cause the RCDs to trip (if you have them).
Do you have any EL or CC tubes in your case? check if one of those may be grounding!
Switch mode PSU are strange things, you can take a +12V wire from one and a ground (or -12V and get 24V )from another (even though they are not connected in any way) and get the full voltage and current from the pair of wires as though they were one PSU
It may be a combination of the PSU and the switch mode power supply on the mobo, try a different PSU (might sort it out) though you will probably find nothing wrong with the PSU and will work in another system without the same effect.
SS |
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Zero_Fresh
UberTweaker
Joined: 21 Jul 2004
Posts: 1450
Location: Between PA and the ocean
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| Posted: Mon Aug 30, 2004 1:49 pm Post subject: |
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THIS IS A COMPLETE GUESS
Is it possible that static electricity can flow from the monitor vie the cable to the case? Maybe it is getting worse due to an evergrowing malfunction that is just now becoming apparent? Yeah I know this one is a stretch, but who knows right??
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ToggleHead
TWEAKGURU
Joined: 03 Mar 2004
Posts: 4360
Location: Jersey
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| Posted: Mon Aug 30, 2004 2:06 pm Post subject: |
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yes i believe that IS possible...but not for me......this happenes without the monitor plugged in
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[KoG]^weaZel
TWEAKGURU
Joined: 31 Oct 2003
Posts: 3296
Location: IRC ETG #kog
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| Posted: Mon Aug 30, 2004 2:36 pm Post subject: |
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yeah Sparky errr TH, I didnt have any troubles with it shocking me in the 2 cases that I had it installed in.
Did you use the same power cord that you used on the other psu's?
Might try unplugging some of the other devices in your computer too. It might be a cd-rom or a floppy that has gone south. Also make sure that none of the wires have been pinched and might be grounding somewhat. It is all worth a try.
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I tweaked and it tweaked back! So I Tweaked some more!
"Barney is like the Michael Jackson of PBS." - James Tybeerious |
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2old2care
Lord of the Tweak
Joined: 09 Jul 2004
Posts: 2817
Location: Pssst....Over Here
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| Posted: Mon Aug 30, 2004 2:44 pm Post subject: |
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HA HA..  ..good mod weaZ.... the "Domo shock control mod". ....Awesome.
SS brings up the light question also, not a bad idea. Any CCFL crap in there? We had the thread about the quality of them. Ixnay all the ullshitnay?
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ToggleHead
TWEAKGURU
Joined: 03 Mar 2004
Posts: 4360
Location: Jersey
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| Posted: Mon Aug 30, 2004 2:44 pm Post subject: |
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no man there are no wires crimped or anything like that.......it may be one of those cold cathodes in there or something but still this is a little tough to wrap my faith around this one....lol
i'll keep you guys posted...=P
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