Electricity Issues- Got a Shock !

[Natemeister]

Got a shock ( electrical) working on my PC.

Got my voltmeter out and connected one end to a ground and the positive to my PC and it read 120 volts( huh??).

I tried same on other PC and read the same.

Test the ground on my receptacles and the ground is OK/normal//working.

I noticed the problem when connecting my ATI AIW 9800 card to my tv cable. It sparks big time.

It's not the ATI card- because when I ran some tests with my voltmeter ( as above) I get a 120 volt reading.

Now - when I touch the case- I do not get a shock.

I don't get it- cause my PC power supply supplies 12 volt and 5 volts.

Incidently, if I run the voltmeter test to my monitor vga plug it reads 120 volts ( when other lead is to ground).

What going on here ? Should not be normal to get sparks/arcing when connecting my PC to the tv cable.

 

[Matthias99]

Originally posted by: Natemeister
Got a shock ( electrical) working on my PC.

Got my voltmeter out and connected one end to a ground and the positive to my PC and it read 120 volts( huh??).

I tried same on other PC and read the same.

Test the ground on my receptacles and the ground is OK/normal//working.

I noticed the problem when connecting my ATI AIW 9800 card to my tv cable. It sparks big time.

It's not the ATI card- because when I ran some tests with my voltmeter ( as above) I get a 120 volt reading.

Now - when I touch the case- I do not get a shock.

I don't get it- cause my PC power supply supplies 12 volt and 5 volts.

Incidently, if I run the voltmeter test to my monitor vga plug it reads 120 volts ( when other lead is to ground).

What going on here ? Should not be normal to get sparks/arcing when connecting my PC to the tv cable.

Grounding problem to the case, almost certainly. Make sure you don't have any loose screws, etc. floating around in there (possibly wedged under the motheboard), and that you installed all the standoffs correctly.

And are you measuring in AC or DC on that multimeter?

 

[CraigRT]

good god that is not normal.. touch the wrong thing and your whole PC could go up in flames, from what it sounds like!

 

[Bozo Galora]

yeah, that was my first thought - wrong vom setting
if case was 120v - poster wouldnt be posting
prob shuffling accross carpet

tho psu might be leaking to case if both boxes have same model
need to go to hw store and get ground fault plug socket tester

 

[thirdlegstump]

It could be electric problem. Call electric man.

 

[Natemeister]

Bought a ground tester and all my plugs check out A'OK - the ground is working.

Pulled a third PC out of the closet and powered it up. Ran the same test - volvmeter negative connected to grounded wire and positive to PC case. Voltmeter reads 120 volts.

Yes- voltmeter set to AC.

MB's all secured with the normal metal standoff.


I do not get a shock when touchin the case- only when touching case and grounded.

I do not get what is going on.

Happens with or without PSU powered- it happens with monitor vga plug in the card and PSU unplugged and vice versa.

I was thinking bad ground - but the tester I got show correct ground.

Can someone try the same test with a voltmeter and report readings??

Thanks

 

[Natemeister]

Grounding problem to the case, almost certainly. Make sure you don't have any loose screws, etc. floating around in there (possibly wedged under the motheboard), and that you installed all the standoffs correctly.

And are you measuring in AC or DC on that multimeter?
[/quote]


Am measuring AC on voltmeter.

Please explain correct installation of MB standoffs. I use the copper colored metal ones with screws thru the MB to the standoff. How else would this be done?

Plus- if problem was from MB, wouldn't that be about 12 volts AC and not 120 volts AC ( same as my electrical outlets).

 

[Terumo]

If it happens with the PSU turned off, it sure sounds like a wiring proble -- either a power strip or home wiring.

If you're living in an older home/apartment your wiring may not be able to handle the power drain of modern hardware. It may not be noticeable until something goes wrong.

Couple years ago we had a problem with power going nuts (Halloween anyone?), and it was related to a faulty transformer of the power company. After a portable generator and line conditioner was installed (took them 2 weeks to fix the transformer), all the problems went away. So home wiring (or some problem with the electrial grid to your home) is one of those hidden problems that often goes unnoticed in hardware failures -- in this case, your ground may have also been fried.

If you can't find the problem quickly, get an electrician to come out and test it for you. Last thing you want is to lose your residence to arcing. Believe me, a little shock is an indicator of something larger.

 

[Bozo Galora]

Originally posted by: Natemeister


Am measuring AC on voltmeter.

Please explain correct installation of MB standoffs. I use the copper colored metal ones with screws thru the MB to the standoff. How else would this be done?

Plus- if problem was from MB, wouldn't that be about 12 volts AC and not 120 volts AC ( same as my electrical outlets).

you might be measuring something unmeasureable and meter defaults
try putting vom with one end in wall socket ground, other on metal case bottom of stereo receiver or something

 

[Natemeister]

you might be measuring something unmeasureable and meter defaults
try putting vom with one end in wall socket ground, other on metal case bottom of stereo receiver or something
[/quote]



When I connect the ground to wall socked ground and positive to PC case I only get a small/ nominal ac volt reading.

However, when using the ground wire that I nailed into the earth - I get a 119 volt ac reading. With alligator clips- I can power a desk lamp with the plug clipped to my ground waire and the other to my case.


Even though my ground tester shows CORRECT for ground- I am suspicious that the grounding in my house wiring is suspect/weak/inadequate.

I just cannot figure what else can be going on.

 

[Natemeister]

Believe I have isolated the problem to bad house wire grounding in my study.

Tried another outlet with a long heavy duty extension cord - volvmeter is normal.

Wonder why my plug tester shwoed my study plugs to be OK ??

Oh well- I will need to call an electrician.

 

[Matthias99]

Originally posted by: Natemeister
Believe I have isolated the problem to bad house wire grounding in my study.

Tried another outlet with a long heavy duty extension cord - volvmeter is normal.

Wonder why my plug tester shwoed my study plugs to be OK ??

Oh well- I will need to call an electrician.

The plug tester tester only tests the ground relative to the outlet (it ensures that, roughly, outlet 'hot' - outlet 'ground' = 120VAC). It sounds like your issue is that your outlet ground itself is hot, which needs to be fixed, preferably by a competent electrician.

 

[Terumo]

Originally posted by: Natemeister
Believe I have isolated the problem to bad house wire grounding in my study.

Tried another outlet with a long heavy duty extension cord - volvmeter is normal.

Wonder why my plug tester shwoed my study plugs to be OK ??

Oh well- I will need to call an electrician.

Do you know what else is sharing the same circuit (like a 220v appliance in the kitchen)? I don't mean to scare you, but if you have a wiring problem it needs to fixed quick. I'm not joking. We lost a home to electrical arcing of a burnt out socket (caused by a kitchen fire, and the fire department didn't pull the breaker box afterwards keeping it live).

If we didn't decide to stay in a hotel that night, I wouldn't be here today to type this. Completely burned down the house 3 in the morning.

So when there's home wiring problem get it fixed quick. No point being a He-Man if you're dead!!

 

[Natemeister]

Electrician is scheduled for early morning tomorrow.


I totally agree with you- electricity can be a handfull when it's wired wrong.

 

[Natemeister]

The plug tester tester only tests the ground relative to the outlet (it ensures that, roughly, outlet 'hot' - outlet 'ground' = 120VAC). It sounds like your issue is that your outlet ground itself is hot, which needs to be fixed, preferably by a competent electrician.[/quote]


Thanks - I have an electrician scheduled for the AM.

I'll report /post back the findings.

 

[Natemeister]

electrical problems solved !

Electrician came to house and determined the wiring was indeed screwed up in the area of my house where my PC's run. Amazingly, for at least the past 15 years the wiring was screwed up majorly. The neutral and ground wires were crossed resulteting in a hot ground wire ( bad bad bad). Also the polarity was reveres on all plugs.

Luckily- no damage to PC equipment, my family. or property ( from fire).

Best $230 I ever spennt for the 4 hours it took the electrician to correct my house wiring.


Do yourselve a big favor and have an electrician check out your house wiring every few years........

 

[walkure]

Wow... I'm also concerned about this in my house.

My house is kinda old, and we've had at least 2 different electricians here in the past (but not in at least 7 years). They both did some rewiring or something, because a long time ago, it seems that some circuits were totally overloaded, so for example in the summer, with the central air conditioning running, and also a lot of lights, etc, we would blow the fuse.

Lately, when I put bread in my toaster and pull the lever down, the light on my kitchen ceiling gets brighter than normal! WTF!!?


Luckily I have an electrician friend who lives just down the block... I think I need to have him check this stuff.

 

[Bozo Galora]

holy guacamole!

 

[JimPhelpsMI]

Hi Walkure, You have lost a neutral connection, probably at the main electrical panel. The two halves of the 240 coming in are in series with each other. When you increase the load on one side the voltage drops on the other side. When you decrease the load on one side the voltage on the other side rises. Call your good friend quick and get it fixed. Jim