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My old cat chewed up the audio cable from the headset itself and bit through the wire. I found a 5 wire cable and bought some replacement 3.5mm TRRS jacks and replaced the whole wire and jack with them. The sound works perfectly fine but when i try to test the mic, it doesn’t pick up anything. I wired everything up in the way its supposed to be wired up. Ideas anyone?

Clearly, your cat considers that the cat food you provide isn’t of sufficient quality ;-) If you can disassemble the headset you can use a testmeter to check for continuity from the mic itself (or close) right through to the jack and hopefully narrow down the fault. The multi-stranded wire used in headphones is tricky to solder and it’s easy to get a tiny solder bridge, or one strand touching where it shouldn’t, or it could even be a faulty jack. Also, check there aren’t any shorts between any of the T, R, R and S - in fact, try that first! Or maybe the cat chewed somewhere else you didn’t notice.