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I have an aluminum PC case. Whenever the metal USB plug from my external drive contacts the front, I get crackling from my speakers, which are connected to an external USB soundcard. (This crackling happens even if they're not connected to the actual output jack.) A few possibly related problems: my audio occasionally starts popping once every few minutes, and my USB devices sometimes play the "connected" sound in Windows even though they're already connected, as if they're briefly disconnecting.

My guess is that this has to do with the grounding, but I'm not sure exactly what to do. My case has a round grounding wire, but I don't know where to attach it, and fiddling with it didn't seem to have any effect. Suggestions?

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Can you post a link to a picture? – ChrisF Nov 1 '09 at 22:23
definitely sounds like grounding problems; get a ground tester from your local Home Depot or equivalent and check your wall socket for proper ground. – quack quixote Nov 1 '09 at 23:22
It's happened in more than one house, though. I suspect it has more to do with my setup than the house. – Archagon Nov 2 '09 at 0:16
hmm. you're right, more to do with your setup. did you build the PC? sounds like the motherboard isn't mounted properly, or maybe that mystery ground wire should connect case to PSU. check for manuals for your case/mobo/PSU -- i'd teardown & rebuild that PC. – quack quixote Nov 3 '09 at 3:57
up vote 1 down vote accepted

Fixed it. Turned out that the front panel had a grounding wire that needed to be connected to a case screw.

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Sounds like a inter-computer problem? All speakers will pop if they come in contact with an electrical source,( like touching the two poles on the aux cable), or plugging them into a jack. If your speakers pop when you plug a USB into the front then there must be a connection between the usb and the sound card jack.

If the two usb jacks are together then the metal housing for both may be one piece, in which the only thing you can do to fix the problem is to put some electrical tape on the base of the male usb plug,(not covering the whole thing, just a portion) this will prevent electrons from flowing from usb port to usb port. Experiment with the amount of tape on the end to allow data transfer but prevent it from contacting the metal housing.

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