Nokia BH-104A hard reset
To repair and reset your Nokia BH-104A:
Clear settings or reset
To delete the pairings from the headset when it is switched off, press and hold the power key and the answer/end key (for about 5
seconds) until the red and green indicator lights start to alternate.
To reset the headset if it stops functioning, even though it is charged, connect the headset to a charger while you press and hold the power key.