PC keep restarting. Electric through the casing.

Toggle sidebar Toggle sidebar
servarus

servarus

Distinguished
Jun 3, 2010
136
0
18,690
I just upgraded two new PC - changing the motherboard and CPU.

After that we had problems with one of the PC - the PC kept restarting sometimes not even pass the Windows Logo.

Then I found out there's electric current flowing through the case - does it have anything to do with it?
 
Solution
InvalidError
The problem is the lack of a good ground between the PC case and Earth ground. The cause could be a missing or weak connection in the PSU, the power cord, power bar, the power outlet, building wiring or building ground.

Since your PC is connected to a monitor through a shielded cable and the monitor most likely uses a C15 type grounded power plug to the same outlet/bar your PC is connected to, you should be feeling the same buzz from touching exposed metal on the monitor too. This means that the bad ground is either in the power bar or upstream from there.
Sort by date Sort by votes
Supahos

Supahos

Expert
Ambassador
Nov 11, 2013
12,756
48
57,640
First, did you reinstall windows? If you changed boards you probably should... And please describe how you came to know of the electrical current I'm the case... That is a major issue if you are correct. Did you just screw your motherboard to the tray? Or use the little brass things to make it have some clearance
 
Upvote 0 Downvote
InvalidError

InvalidError

Titan
Moderator
May 18, 2007
23,815
5,265
108,890
If you "feel electricity" when touching the case, it means you have a bad chassis ground and the PC is a risk of shock hazard. You need to find where the bad ground comes from. It could be that the ground pin/wire inside the PSU is not correctly connected to chassis, that there is no good enough connection from the PSU to the chassis due to painted parts, a bad power cable or bad/no ground in the building's wiring.

Is it the cause of your restarts? Maybe. Having the whole system riding on a high enough chassis voltage to be felt by touch (that typically means over 40V AC) isn't going to help stability.
 
Upvote 0 Downvote
servarus

servarus

Distinguished
Jun 3, 2010
136
0
18,690

I actually didn't install Windows back because the other PC after I changed it (different Windows version though) is fine. This PC that is having problem was fine until the next day... I attempted to reinstall the Windows, but it keeps crashing after loading.

The Windows also sometimes can boot but after a while it will restart and then it restarts randomly - usually post Windows logo.

Anyways, I was handling the casing and I kept getting static shock. Then I use a test pen and check the whole chasis and it lights up almost everywhere.

I screw my motherboard using the brass thing. The electric shock only happens when I plug the 12 pin.
 
Upvote 0 Downvote
servarus

servarus

Distinguished
Jun 3, 2010
136
0
18,690


I'm not sure about the grounding - is there any explanation about this? I noticed that the electric only is there when I plug in the 12 pin to the motherboard.
 
Upvote 0 Downvote
InvalidError

InvalidError

Titan
Moderator
May 18, 2007
23,815
5,265
108,890

PSUs have noise suppression capacitors between live, neutral and ground. If the ground connection is bad for whatever reason, you end up with a voltage divider. The "electricity" you feel is the leakage current from that divider which would normally go to ground.

If you only feel it when the ATX connector is plugged in, it means that there is a poor connection between PSU ground and the computer case. As I wrote earlier, that poor connection can be caused by something as simple as paint. There is also the possibility of a manufacturing defect where the ground bond between the IEC plug and PSU is missing altogether. If you have a multimeter, you should be seeing a dead short between the IEC plug ground, PSU enclosure and the black wires on the output.
 
Upvote 0 Downvote
servarus

servarus

Distinguished
Jun 3, 2010
136
0
18,690

I see... I'm not sure about the problem, but I will try with different PSU and/or casing and report back.
 
Upvote 0 Downvote
servarus

servarus

Distinguished
Jun 3, 2010
136
0
18,690
I found out that I was missing one connector pin (motherboard to casing) and after I added one more pin - the PC seems to be working well - but there's still electricity running throught he metal case.

I guess the problem is the casing now?
 
Upvote 0 Downvote
InvalidError

InvalidError

Titan
Moderator
May 18, 2007
23,815
5,265
108,890
The problem is the lack of a good ground between the PC case and Earth ground. The cause could be a missing or weak connection in the PSU, the power cord, power bar, the power outlet, building wiring or building ground.

Since your PC is connected to a monitor through a shielded cable and the monitor most likely uses a C15 type grounded power plug to the same outlet/bar your PC is connected to, you should be feeling the same buzz from touching exposed metal on the monitor too. This means that the bad ground is either in the power bar or upstream from there.
 
Upvote 0 Downvote
Solution
Faux_Grey

Faux_Grey

Honorable
Sep 1, 2012
747
1
11,360
If there was no electric shock before you upgraded, you might have a short somewhere behind the motherboard, as well as a faulty grounding system from the PSU.

I would suggest you use a different cable to plug the PC in, as well as a different wall socket, and if you're using a multiplug, get rid of it. (usually find cheap multiplugs losing their ground wire)
 
Upvote 0 Downvote
You must log in or register to reply here.

TRENDING THREADS

Latest posts

Moderators online

Share this page

COMPANY
RESOURCES
FOLLOW
Top Bottom