Won't turn on, only works with cable.
Already tried hard and soft resetting it, with no luck. Light turns red when charging. Just won't turn on.
"Ok, so I also have this problem.
I've removed the left cushion, taken out the 4 screws that secure the backside and opened it carefully. I originally suspected waterdamage but couldn't find anything on the circuit board. Also removed the 2 screws holding the circuit board down and looked under it, still no water damage to be found.
After this I tried to disconnect the button ribbon cable but ultimately didn't proceed as I didn't know how to disconnect it without damaging the connector.
Not sure how to proceed I tried a Hail Mary power button press and to my surprise… it turned on. Not sure what I did exactly I just closed it and enjoyed my working headphones again.
This was all yesterday. Today I came back from work, tried to power up the headphones, and nothing. Just noticed a faint blue light for a millisec. Opened it back up and tried moving cables etc. while pressing the power button and it turned on while applying pressure to the button ribbon connector. After closing it back up I'm able to power it up and down without problems.
Still not sure what is wrong and not hopeful it will still turn on tomorrow but at least I got a lead.
Edit: Turning it off and leaving it for 15 minutes causes it to return to the broken state. After this it needs to be opened up and pressure applied to the button flex connector. Not sure what's wrong still. Will try to remove the circuit board completely next."