What does the white indicator light on the B2 rear panel mean?
If it's on and solid, this means the B2 is powered on, and currently connected to a Bluetooth-enabled device.
If it's on and blinking, this means the B2 is powered on but not currently connected to a device.
If it's off (and B2 is powered on), this means Bluetooth is in standby and not connected to a device. The B2, however, is still visible to your device, so simply connect using your device and it will automatically wake up.