From one teardown I’ve seen, the ear pads are replaceable. Try carefully prying it up and then there should be I think torque screws underneath. From that teardown, the cable looks pretty loose and secure, so it does seem like the twisting and turning of the yokes (along with adjusting it a 1000 times to put it in the hard case) would be the culprit. Look in there and see if the two wires going to the driver are connected, or if there’s a break in the cable. Also before doing this, check if the noise cancelling feature works on both sides or one side, it should be easy to tell since one side should be louder.