PSU Whining/Squealing Noise - Grounding issue?

[aleros805]

Hey guys,

I've been having some trouble lately. I use ventrilo a lot for gaming and it seems there is some sort of whining coming out of my mic. I isolated the problem and it seems to be coming from the PSU strangely enough.

Whenever I disconnect my Ethernet cable from the pc a squealing noise starts coming out of the PSU the same noise that comes out of the microphone. (recorded myself). Once I connect the ethernet cable the noise goes away from the psu. When I dont have the ethernet connected there is no noise on my mic when I record myself.

I'm assuming this is some sort of grounding problem as my cable modem probably does the grounding, and without it the noise. Is there anyway I can fix this? I'd like to keep the ethernet connected and not have the mic noise.

Thanks

 

[Paperdoc]

Id does sound like your machine is not grounded at all, except through the Ethernet cable, which is scary wrong! I assume you have a normal power cable from the wall outlet to the machine, with three wires internally and a Ground prong on the plug. So that leads to the question, why is there no apparent Ground connection? Do you have some intervening devices, like multi-outlet power bars or something, that night have a fault the breaks the Ground connection? Does the wall outlet you use actually have a proper Ground it it? You can buy a relatively cheap plug-in device to test the wall outlet - its pattern of lights tells you of any problem. The same unit can be used to test any other outlet, like the end of an extension cord or a Power Bar outlet.

If all of the power cord tests say your supply wiring is OK, see if you can verify that the power cord Ground lead (plug's long round prong) actually is connected to the outside chassis case of your computer.

Is there any chance that you have peripherals (like a printer, or an audio system connected by an audio signal cable) plugged into a DIFFERENT wall circuit? Sometimes this sort of system can result in "Ground loops" - circuit paths that allow small currents to flow between unbalanced Neutral connections, that end up acting as low-voltage signal sources for amplifiers.

 

[aleros805]

I pretty much have everything on one regular outlet strip, I just moved so kinda messy, but all I could find atm. I'm assuming i should use a special grounded one for all my devices? Or can I just plug the pc to the wall and that will ground it?

 

[Paperdoc]

As long as the power bar has a normal 3-wire supply cord with a 3-prong plug, your equipment is grounded though it just as well as if you plug directly into the wall (assuming there's no flaw in the power strip, of course). You "just moved", so what do you know about the wiring in the house / apartment? Some older buildings have no Ground leads in the wiring, but someone has changed the wall outlets to 3-prong just to accommodate the plugs without actually providing a Ground connection. Again, one of those outlet checkers from a hardware store will allow you to test any outlet.