Chasis is live!

[DoomsWord89]

Hello!

I recently buily a computer for my brother and found out the hard way that the case was live .

When I would touch the chasis I would get a slight tingle.

So, naturally I turned the computer off and did not turn it back on for several days, until I had some idea of what could be wrong.

After pulling several pieces of hardware, I noticed that the problem no long persisted.

After narrowing down what hardware could be causing this I found that after removing the GPU and testing the chasis the problem no longer persisted.

I am quite sure I have the problem well in hand (or not?) , however I am not sure what would cause the GPU to do this.

Also, there were two HIS 6850s in the computer and only one seems to be the cause of this issue.

Any ideas?

 

[RetiredChief]

A component problem should not cause this - Your chassis SHOULD be tied to earth ground which means that the voltage on your chassis should be less than 1 volt. UNLESS you have a grounding problem with your house wiring. USA - 3 wire outlet, one hot (!20 VAC, one nuetral (should be very close to Zero V) and one earth ground (0 volts. There should be zero ohms diff between your chassis and the earth ground. Erth ground is tied to PSU chassis and that in turn to the Computer case.

One - you have a problem with house wiring or you have an open in the line.

 

[hunter315]

Is your power supply mounted properly? The screws that connect it to the chassis tie them together electrically, the casing of the PSU is tied directly to the ground wire, if its all mounted together properly and there is still charge on your case then something in your PSU is bad and this is very bad as it means that there is a chance that the 380V inside could get shorted to the casing which would be very bad for you.

 

[Crashman]

Hello!

I recently buily a computer for my brother and found out the hard way that the case was live .

When I would touch the chasis I would get a slight tingle.

So, naturally I turned the computer off and did not turn it back on for several days, until I had some idea of what could be wrong.

After pulling several pieces of hardware, I noticed that the problem no long persisted.

After narrowing down what hardware could be causing this I found that after removing the GPU and testing the chasis the problem no longer persisted.

I am quite sure I have the problem well in hand (or not?) , however I am not sure what would cause the GPU to do this.

Also, there were two HIS 6850s in the computer and only one seems to be the cause of this issue.

Any ideas?

Chassis is grounded to power supply. Power supply is grounded via the third wire to the wall's power outlet. Are you using an adapter to circumvent that connection, perhaps on a 2-prong wall outlet?

If you have a 3-prong wall outlet, your building probably has a wiring problem that could cause a fire, while you sleep peacefully, never to awaken again.

 

[iam2thecrowe]

power supply/earthing problem.

 

[HEXiT]

if you plug in the gpu and your then getting shocks it means the gpu is earthing to the case. sounds like something in the gpu is earthing against the cooler or some other outer surface... i would rma it asap. as it sounds like a build quality problem.

i would also check the connectors from the psu. try the 1s from the other card, if the problem persists its the gpu, if it stops then its the connector from the psu.

 

[Crashman]

if you plug in the gpu and your then getting shocks it means the gpu is earthing to the case. sounds like something in the gpu is earthing against the cooler or some other outer surface... i would rma it asap. as it sounds like a build quality problem.

i would also check the connectors from the psu. try the 1s from the other card, if the problem persists its the gpu, if it stops then its the connector from the psu.

What you're saying is impossible. Think about it: The case is EARTH GROUNDED as long as his properly-functioning 3-wire cable is connected to a properly-functioning 3-prong wall jack. You can't "charge" the case with another component as that charge would be drained to EARTH ground.

 

[jsc]

The guys above are correct. Something is not properly grounded:

Working from the wall:
AC outlet - check by moving the PC to another circuit - I suggest the kitchen. If the outlet is the problem, call an electrician. If you do not have the skill and knowledge to diagnose the problem, you shouldn't try to fix the problem.

Adapters - You should not be using those old 3 prong to 2 prong adapters - they are not safe.

Power strip - bypass by connecting system directly to wall.

Computer power cord - replace.

PSU not properly installed in case - not too likely because it should have 4 screws holding it to the case.
Defective power supply - test by substitution. A PSU that works except for causing tingly shocks is defective.

 

[Crashman]

The guys above are correct. Something is not properly grounded:

Working from the wall:
AC outlet - check by moving the PC to another circuit - I suggest the kitchen. If the outlet is the problem, call an electrician. If you do not have the skill and knowledge to diagnose the problem, you shouldn't try to fix the problem.

Adapters - You should not be using those old 3 prong to 2 prong adapters - they are not safe.

Power strip - bypass by connecting system directly to wall.

Computer power cord - replace.

PSU not properly installed in case - not too likely because it should have 4 screws holding it to the case.
Defective power supply - test by substitution. A PSU that works except for causing tingly shocks is defective.

Wow, on that last part I never thought about the power supply's "ground strap" being improperly connected...good call!

 

[johnnyq1233]

You could also run out and buy an outlet tester such as this...
http://www.outlettester.com/
They are fairly cheap and any hardware store such as Rona, Home hardware or electrical store should have these.

JQ

 

[DoomsWord89]

Best answer selected by DoomsWord89.

 

[HEXiT]

What you're saying is impossible. Think about it: The case is EARTH GROUNDED as long as his properly-functioning 3-wire cable is connected to a properly-functioning 3-prong wall jack. You can't "charge" the case with another component as that charge would be drained to EARTH ground.

i live in the uk m8 we only use 2 wires live and neutral on the most part. so when you get a shock from the case it genraly means its using you to ground out.

 

[Crashman]

i live in the uk m8 we only use 2 wires live and neutral on the most part. so when you get a shock from the case it genraly means its using you to ground out.

What a screwed-up system! We added the earth-ground to most houses around 40-50 years ago, to prevent that occurrence.

 

[RetiredChief]

Back of my mind, in UK I thought Nuetral was tied to Ground. Primary difference (beside the 50/60 Hz) was that Voltage was single phase, ie lamps and Hot water heater both used 220/240 - Hot = 220/240. In US it is two phase, that is normal circuits 110/120 VAC and hot water heater/ stove where 220/240 - two Hot 110/120 which are 180 degrees out of phase. one half of the house uses one phase, the other half the 2nd phase - to balance current.

My power to the house got cut (tree fell on power line) - good old power company came out and repair. Everythin in the house worked EXCEPT the stove and the Hotwater heater. They had connected both Hots to the same phase.

 

[HEXiT]

yeah its 240v AC @13A-32A for wall sockets to cookers and showers with a 60A max cap fuse in your average uk house fusebox.
and yeah things that tend to use very high wattages tend to have an earth. but things like tv's and other entertainment devices tend only to have the 2...

so in the uk you either see a blue spark if it pops or blue lights when you touch it :lol:

 

[jsc]

Wow, on that last part I never thought about the power supply's "ground strap" being improperly connected...good call!

Everything that I have mentioned, I have seen.

DoomsWorld, what was the problem?
And thanks.