My son bought this USB microphone for his computer. It only works if you keep your hand on the volume knob. I assume this is a grounding problem. I took it apart. It looks like the copper wire attached to the housing is there for grounding – it attaches near the rear of the volume knob. But touching that wire or touching any part of the interior of the knob does nothing to get the sound to work; only the front of the knob makes the sound come through. What can I connect to what to get it to work without having to put a finger on this thing? Thanks!
Best Answer
If it is a grounding issue, touching it could change the amount of hum, buzz or interference.
However you say "It only works if you keep your hand on the volume knob" which I interpret as "there is sound only when the hand is on the volume knob, otherwise there is no sound."
If this is the case, then I'd suspect a bad contact perhaps at the pot wiper, or a cold/broken solder joint that makes contact only when the volume pot is messed with.
You can check this by touching the volume pot with a non-conductive object like a plastic rod. You can use the shell of a ball point pen, or a toothpick for example. If wiggling the knob around with a non-conductive object results in the sound turning abruptly on or off, then you can rule out any influence from your conductive finger, it'll probably be a bad contact.
If the failing contact is at the pot wiper, it will depend on the pot's position. So if the problem does not depend on the pot's setting, it is more likely this is a bad solder joint on the board.