How to perform a factory reset
If you are having issues with the headphones not responding, you can perform a hardware or factory reset to solve the issue:
Push and hold the M-button while pushing the control knob downward to perform a hardware reset.
If the issue persists, perform a factory reset. Push and hold both the M-button and the control knob for 7 seconds until the LED indicator turns purple.
Note: The factory reset will delete all user settings, and the headphones will need to be set up again.