Initializing the headset to restore factory settings
Remove the headset from the charging case to turn off the headset by pressing and holding the button on the left unit for more than 2 seconds. (Both the left unit and the right unit are turned off.) And then press and hold the button on the right unit and the button on the left unit simultaneously for more than 15 seconds.
The indicator (red) goes into the flashing state then the indicator (blue) flashes 4 times ( ), and the headset is reset to the factory settings. All pairing information is deleted. In this case, delete the pairing information of the headset from the Bluetooth device, and then pair them again.
If initialization is not completed correctly, such as when you release your finger from the button during initialization, the indicator (red) will remain lit.
In this case, place the headset into the charging case and perform the initializing operation again.
If the headset does not operate correctly even after initializing, consult your nearest Sony dealer.