1. Unlock the screen of the Android smartphone if it is locked.
2. Turn on the headset. Press and hold the (power) button for about 2 seconds
3. Display the devices paired with the Android smartphone. Select [Settings] - [Device connection] - [Bluetooth]. Touch [WI-XB400].
If the headset cannot be turned on or cannot be operated even when it is turned on, press both the (power) button and the - button simultaneously while charging. The headset will be reset. The device registration (pairing) information is not deleted.