Sennheiser PX210 BT Repair
My PX210 BTs developed a fault with the left ear, I didn’t want to pay £60 for an official service so I put them to one side. After a while I decided to attempt a repair.
Then remove the control board from the right ear (another 3 t5s), and flip over the board from the left ear.
You now have access to both ends of the multi strand cable that goes over the headband, test each connection with a multimeter. I had a bad connection with one of the inner cables at the left end so I re soldered it by heating the existing solder and reattaching the cable – no additional solder was required.
When reassembling, ensure the white button spacer in the right ear is correctly aligned – it only fits in one orientation.
It’s also important that the two lugs by the battery insertion point are matched when reassembling the left side, otherwise the battery won’t lock in correctly.
After reassembly, both sides worked again 🙂
Full marks to sennheiser for making things repairable rather than disposable.
Incidently if you need to test both sides of headphones from an iPhone, the balance is in Settings > general > accessibility.