Initializing the headset to restore factory settings
If the headset does not operate correctly even after resetting, initialize the headset.
-
Turn off the headset.
Remove the USB Type-C cable.
-
Press and hold the
(power) button and the CHAT button for about 10 seconds. 
When initializing is complete, the
(power) indicator (white) flashes 4 times. 
This operation resets volume settings, etc. to the factory settings.
If the headset does not operate correctly even after initializing, consult your nearest Sony dealer.