I have a headset for my desktop computer. It's an analog device with two 3.5mm jacks, one for the headset, one for the microphone. It also has inline volume and microphone toggling.
By wire was chewed up by a cat and torn between the headphone jacks and the inline controls.
I have repaired the headset by re-soldering the wires. It works fine…sometimes.
When I plug the headset into one phone, and the microphone into another, I can play audio onto the headset and record my voice just fine on the other phone, with no crossover.
However, when I plug the cables back in to my computer, the headset works just fine, but there is nothing but what sounds like some background interference coming from the microphone when I test it. I have tried it with two sets of audio jacks on the system, both produce the same result.
Why would it work on the two phones, but not on the computer? This isn't making much sense to me and I hope it would to someone else.
Best Answer
I think it sounds like the mic signal and headset ground lines are shorted together. The mic signal will be shorted to ground when both plugged into the same computer (i.e. shared ground)
When they don't share a ground, the problem goes away as the only common signal path is up to the short and should be of negligible resistance.
Testing with a multimeter would confirm this, just touch one probe to the tip of mic jack and other to headset sleeve (The other larger contact - I'm assuming mono TS Jacks, as opposed to TRS jacks)