# PC not grounded right?



## thornygravy (Feb 8, 2007)

Ok, well i bought my computer from gateway about a 3 years ago, and it pretty much owned but i didnt like the case so i bought an x-dreamer. So i took my gateway apart, did some research before I did it and i got everything in there and working and it seemed fine. 

UNTILL! i started to notice that when I touched it that i get a somewhat powerful shock from it. So i just ignored it. Untill I touched it one day and BOOM blew out the front LCD panel and the comp shut off. Still seems to run fine, but I would not like to have to becareful about touching it. 

So, where did i go wrong? and how do I ground it right?

Is it safe to run my computer even if it isnt grounded right?

Thanks In Advance.

System Specs:

-420w PSU
-ATI radeon x800xl AGP 256mb
-P4 2.80gHz dual proccessor
-1gig of system ram


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## PuMA (Feb 9, 2007)

Like u said the case is not grounded right, its no means safe to use ur pc if theres voltage in the case, the FIRST thing to do is to shut it off and do the following: The computer case is grounded via the screws u use to connect the mobo to the case. Check that the screws are tightened right. U could even get the mobo off the case and install it again, make sure the screws are tightened.


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## Lazzer408 (Feb 9, 2007)

First use a tester like this
http://www.professionalequipment.com/xq/ASP/ProductID.70/id.5/subID.54/qx/default.htm
and verify the outlet is properly polarized/grounded. Then use a meter to test for continuity between the ground pin on your power cord and the case. < 0.5ohm is ideal. If both of these tests pass then the PC is properly grounded. If you are getting a shock touching your computer perhaps the other device your touching at the same time isn't properly grounded. Electricity needs a path. No path=no shock. You can't get shocked from a single connection.


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## PuMA (Feb 9, 2007)

Im thinking u have installed the MOBO the wrong way. result= its not grounded + the mobo conducts electricity in ur case. To be exact im think he has the mobo slightly turned from side towards the case, and the grounding screws are out of place and some soldering touches the case


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## Lazzer408 (Feb 9, 2007)

PuMA said:


> Im thinking u have installed the MOBO the wrong way. result= its not grounded + the mobo conducts electricity in ur case. To be exact im think he has the mobo slightly turned from side towards the case, and the grounding screws are out of place and some soldering touches the case



There's not a high enough voltage on the motherboard to shock you. If any voltage carrying path on the board were touching anywhere on the case it would trip the psu into protect. I'm fairly convinced it's a wiring problem in the house. No ground in the outlet, no ground pin on the plug, a defective power cord, or defective powerstrip if one is being used.


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## PuMA (Feb 9, 2007)

well tell me then how the hell would the 150-230 V from the non-grounded outlet would carry on its way onto the case??? remeber the 150 ( or whatever u use in the america) -230 go only to the transformer which is right after the FUSE in the PSU and after that the voltage is 12V max.

edit: The reason the outlets are grounded is because if u use non-grounded device, when shorted It will blow a fuse in fusebox, preventing the device from (hopely) frying.

edit2: as I said when the mobo/case/psu is grounded right, whenever voltage gets to the case it should blow the fuse in the PSu

edit3: Its not the voltage that gives u the shock-its the ampage that hurts


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## Lazzer408 (Feb 9, 2007)

PuMA said:


> well tell me then how the hell would the 150-230 V from the non-grounded outlet would carry on its way onto the case??? remeber the 150 ( or whatever u use in the america) -230 go only to the transformer which is right after the FUSE in the PSU and after that the voltage is 12V max.
> 
> edit: The reason the outlets are grounded is because if u use non-grounded device, when shorted It will blow a fuse in fusebox, preventing the device from (hopely) frying.
> 
> ...



Puma you need to get a book on electricity and start studying. Amperage eh? A car battery can put out some amperage can it not? Yet I can grab both terminals and feel nothing. Also the ac in the psu does not go to the transformer. After the fuse, it goes to a bridge rectifier, converted to DC, then to a large filter cap to smooth it out, then the now +160v goes to the common center lead of the switching transformer, then outer poles run thru to the drain leads of the switching fets that have there source legs tied back to the cap @ 0v. That alternate 'flip-flop' back and forth at 20khz+ to create the high frequancy "AC" the switching transformer needs in order to get that 80%+ efficiancy a SMPS gives us. Don't argue with an electronics engineer...you'll get PWND again.


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## PuMA (Feb 9, 2007)

ok I dont know "EXACT" details, how ur PSU might work, but don't challenge the simple electrician's mind when drunk    .  The way we build PSu's is 230V to on/off switch to FUSE,to the transformer. After that comes regulator and condensators and stuff.

For the shock thing a static discharge may have 1500V of voltage in em, but u dont feel a thing. After u put some current in u get the shock that feels


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## Lazzer408 (Feb 9, 2007)

Sounds like your building a linear powersupply there. Switched mode is a bit different. I've attached a pic of a quick drawing I just made to help you better understand the front end of a SMPS. The initial regulation/feedback has been omitted. This is just to show the path of the line voltage on the primary side and a quick basics of the secondary side as to how it get's back to DC again.







EDIT "well tell me then how the hell would the 150-230 V from the non-grounded outlet would carry on its way onto the case???" Please note the 1meg resistor that is used in an otherwise isolated powersupply. This can provide a path to ground for low current static charges and whatnot. Some PSUs -might- have the primary and secondary grounds tied together but I have only seen it once or twice in a PC powersupply but it's common in things like TVs to have them tied.


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## Lazzersgirl (Feb 9, 2007)

Quit showing off hunny


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## PuMA (Feb 9, 2007)

I see that this is very accurate PSU,with lot's of fine tuning, with transistors, cap's and resistors. Correct if im wrong but would a correctly grounded device blow a fuse either in fuse box or in the psu when electricity gets in its case or short circuit's??


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## Completely Bonkers (Feb 9, 2007)

What a lot of nonsense in the earlier posts.

If its a metal case... the PSU will touch the case. And the PSU case is grounded (or should be)... so the case is grounded.  

Basically if you are getting a shock from the case there is a problem with the PSU, OR WITH YOU POWER CABLE... OR WITH YOU POWER SOCKET AT THE WALL.

Get your socket checked immediately before SOMETHING ELSE in the house blows up and kills the kids. If the socket is OK... change your cable and throw the old one away. If the cable is OK, buy a new PSU immediately and throw the old PSU away.


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## Lazzer408 (Feb 9, 2007)

PuMA said:


> I see that this is very accurate PSU,with lot's of fine tuning, with transistors, cap's and resistors. Correct if im wrong but would a correctly grounded device blow a fuse either in fuse box or in the psu when electricity gets in its case or short circuit's??



 That schematic is a very simple switched mode power supply. PC powersupplies are much more complex then that. The design your talking about where the AC heads to the transformer first is called a linear power supply. The transformer is simply a step-down from 120-240 to whatever. That design is more common in things like home recievers/amplifiers where voltage or current regulation isn't very critical since it's only driving a speaker not $2000 worth of silicon.  

"would a correctly grounded device blow a fuse either in fuse box or in the psu when electricity gets in its case or short circuit's??"

  In a properly designed computer psu, no. An output short would activate the powersupply's current trip and it would simply turn off. Now, a voltage spike introduced into the powersupply's output from another source could blow a component inside the supply which, in turn, could cause the current protection, or regulation circuit, to fail creating a short inside the powersupply itself. That could blow the fuse in the supply which is a much lower rating then a breaker in the home's panel.


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## PuMA (Feb 9, 2007)

yeah and if that will not work buy new house and kids 

ok lazzer i give up   my head is going fuzzy lol


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## Lazzer408 (Feb 9, 2007)

Completely Bonkers said:


> What a lot of nonsense in the earlier posts.
> 
> If its a metal case... the PSU will touch the case. And the PSU case is grounded (or should be)... so the case is grounded.
> 
> ...



Thanks... that was my first reply to him.


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## PuMA (Feb 9, 2007)

...and my suggestion was that the mobo was shorting the case, but i quess u fancy engineer and ur girl is right


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## Completely Bonkers (Feb 9, 2007)

Well, it looks like 4 experts agree. 

thornygravy would be bonkers not to take our advice.


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## Lazzer408 (Feb 10, 2007)

Completely Bonkers said:


> Well, it looks like 4 experts agree.
> 
> thornygravy would be bonkers not to take our advice.



hear hear


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## Nitro-Max (Feb 10, 2007)

Have You done the fry an egg test? i like mine runny


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## Lazzer408 (Feb 10, 2007)

Nitro-Max said:


> Have You done the fry an egg test? i like mine runny



What's that?


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## Nitro-Max (Feb 10, 2007)

Lazzer408 said:


> What's that?



crack an egg open on the case and see if it cooks


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## Lazzer408 (Feb 10, 2007)

Nitro-Max said:


> crack an egg open on the case and see if it cooks



Ah I see. I think I could fry one on my cpu running 71c  At least till my Infinity gets here.


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## Nitro-Max (Feb 10, 2007)

Lazzer408 said:


> Ah I see. I think I could fry one on my cpu running 71c  At least till my Infinity gets here.



Ouch 71c is a bit hot


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## DRDNA (Feb 10, 2007)

Lazzer408 said:


> Ah I see. I think I could fry one on my cpu running 71c  At least till my Infinity gets here.



VERY nice job if thats a stable rig at 71c 

Usually the hotter the chip the less stable so if your really stable then truely nice tuning
whats the ghz@?


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## Lazzer408 (Feb 10, 2007)

DRDNA said:


> VERY nice job if thats a stable rig at 71c
> 
> Usually the hotter the chip the less stable so if your really stable then truely nice tuning
> whats the ghz@?



All I can say is I've ran 3dmark05, 06, prime95 x2, Super_pi, and no crashes for days and multiplayer gaming for hours at a time. I think it's stable. Hey even the event log is clear.  71 is to hot. I was 63-66c on the BigTyphoon. I'm using a Blue Orb II at the moment till the Infinity gets here. Here's a pic. CPU 1.45, NB is stock at 1.5v, FSB is at 1.4v (+0.2v)


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## DRDNA (Feb 10, 2007)

Lazzer408 said:


> All I can say is I've ran 3dmark05, 06, prime95 x2, Super_pi, and no crashes for days and multiplayer gaming for hours at a time. I think it's stable. Hey even the event log is clear.  71 is to hot. I was 63-66c on the BigTyphoon. I'm using a Blue Orb II at the moment till the Infinity gets here. Here's a pic. CPU 1.45, NB is stock at 1.5v, FSB is at 1.4v (+0.2v)



Man oh man thoughs really are magic chips ,I heard some one ran one with no heat sync and the bugger didnt want to burn up ,lol , it did though.


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## Carcenomy (Feb 10, 2007)

Nice piece of overclocking there Lazzer 

I wonder if the OP guy sorted his shocks out? I suspect cheap-ass PSU that's not grounded internally properly. I've seen it before quite a few times.

At least we're not back in the ol' AT days where if someone took the heatshrink off the power switch they would usually electrocute themselves good...


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## Lazzer408 (Feb 10, 2007)

Carcenomy said:


> Nice piece of overclocking there Lazzer
> 
> I wonder if the OP guy sorted his shocks out? I suspect cheap-ass PSU that's not grounded internally properly. I've seen it before quite a few times.
> 
> At least we're not back in the ol' AT days where if someone took the heatshrink off the power switch they would usually electrocute themselves good...



 wha? heatsink off the power switch? Your not the one who bought muffler bearings and headlight fluid are you?


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## Carcenomy (Feb 10, 2007)

HeatSHRINK, not heatsink 

AT PSUs ran a cable from the AC in to the switch, THEN to the PSU. So if you had no insulation on the switch, you had mains power RIGHT THERE. Nasty if you bumped it without thinking.


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## Lazzer408 (Feb 10, 2007)

Carcenomy said:


> HeatSHRINK, not heatsink
> 
> AT PSUs ran a cable from the AC in to the switch, THEN to the PSU. So if you had no insulation on the switch, you had mains power RIGHT THERE. Nasty if you bumped it without thinking.



 my bad. Yeh I remember it. Both the hot and neutral were on that switch. 120v full swing right there. I've seen a few people remove the wires to take the front cover off the case then connect them wrong and fry that switch good.


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## Carcenomy (Feb 10, 2007)

AT PSUs were good for catching people off-guard. Between the switch and the two-piece plug (remember the almost racist term 'black boys together'?) there was lots of ways you could blow your stuff up really quickly


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## Laurijan (Aug 27, 2017)

i had 3 tvs and with the last 2 a philips and a lg i get screen distortions when the tv is used as pc monitor with not grounded 230v wall outlet. the none normal voltage runs over the hdmi cable because of the psu in tv and psu in pc generating a voltage between them as far as i have heard. now i run an extention cord from kitchen to pc in living room to prevent that


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## dorsetknob (Aug 27, 2017)

*Laurijan*
Have an electrician "Ground the wall outlet and check that all power sockets are Earth linked" ( ie Same Resistance value to Earth)..


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## qubit (Aug 27, 2017)

Great necro revival from a decade ago lol. The OP is a one post wonder, too.

Obviously if one is getting shocks off the case there's a problem with any or all of these things: wall socket, mains lead, or most likely, the PSU. A PC should not be left running in that state.


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## Laurijan (Aug 27, 2017)

dorsetknob said:


> *Laurijan*
> Have an electrician "Ground the wall outlet and check that all power sockets are Earth linked" ( ie Same Resistance value to Earth)..



I opened the outlet cover today and found out that there is no gorund wire inside. so electrcian would be expensive because the wire would have to be added.


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## infrared (Aug 27, 2017)

Laurijan said:


> I opened the outlet cover today and found out that there is no gorund wire inside. so electrcian would be expensive because the wire would have to be added.


If that's true and there's genuinely no ground wire at that socket, don't use it. Ever. Really you should be finding out who the hell wired it and report them, that's extremely dangerous. In fact I'd say it probably wasn't put in by an electrician at all, maybe a previous owner of that house or something that thinks they're good with a screwdriver.

@qubit - I wondered what was up, I read the first post where he said he'd bought a computer with an x800xl ~3 years ago haha  I didn't notice the date on the post!


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## dorsetknob (Aug 27, 2017)

Laurijan said:


> so electrcian would be expensive because the wire would have to be added.


needs to be Sorted by a Qualified person
your just have to grin and bear those costs or you Risk Damage to equipment like PC or Your Heart/nervous system

Do You have life Insurance and is it paid up to date ???



infrared said:


> @qubit - I wondered what was up, I read the first post where he said he'd bought a computer with an x800xl ~3 years ago haha  I didn't notice the date on the post!


neither did i  and if i had i would not mentioned it ( in Case some one got stroppy with me)


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## silkstone (Aug 27, 2017)

Grounding is over-rated /s.

Everything here runs on a 2-pin system despite new houses/apartments being installed with ground wires.

Funny story, we just moved into a new apartment. I 'checked' all the wiring before buying to make sure that the electrical system was grounded.
By checked, I mean that I'd inspected the socket and seen that there was a ground wire.

So we moved in and after setting up my computer, I was getting intermittent shocks from my case. I thought maybe I had missed checking an outlet and got my cousin to check everything. All looked good.
The problem wasn't occurring all the time and I was too busy to check more so I just put it down to the UPS behaving badly and made a note to replace it.

A couple of days later, I install a dishwasher in the house. All is good until I touch the inside and ZAP! Big bastard electric shock down the left-hand side of my body.
I check a few more times (with the right hand this time) and realize, yup, it's there's definitely AC running thru it.

I take out the voltmeter and hook it up (after accidentally getting shocked a few more times) and see that there's 120+ V running through the metal parts. I check a few other things and they're all the same, despite the ground pin and wire being present.

So I call maintenance to come up and check and try to figure out what the hell is going on. They open the breaker box and see that the ground wire is just loose inside.

The original electrician didn't bother to connect it when the house was done.

As everything here runs on 2-pin, I'm pretty sure mine isn't the only apartment with this problem, I'm likely just the only one who has noticed it.


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## dorsetknob (Aug 27, 2017)

silkstone said:


> A couple of days later, I install a dishwasher in the house. All is good until I touch the inside and ZAP! Big bastard electric shock down the left-hand side of my body.


Imagine that harping to a young Child or Elderly relative



silkstone said:


> I take out the voltmeter and hook it up (after accidentally getting shocked a few more times) and see that there's 120+ V running through the metal parts. I check a few other things and they're all the same, despite the ground pin and wire being present.





silkstone said:


> Grounding is over-rated /s.


You still Believe that



silkstone said:


> So I call maintenance to come up and check and try to figure out what the hell is going on. They open the breaker box and see that the ground wire is just loose inside.






silkstone said:


> The original electrician didn't bother to connect it when the house was done.


Sad to Say then he was not a proper and/ or competent qualified Electrician


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## infrared (Aug 27, 2017)

Yup, don't take chances with electricity. If your wiring is dodgey get it sorted.

Closing this old necro up now.


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