3. Volume up button:long press to increase the volume level rapidly, short press to increase the volume level step by step. 4. Volume down button:long press to decrease the volume level rapidly, short press to decrease the volume level step by step. 11. USB and ARC have automatic detection function. When USB and ARC are not connected, the remote controller cannot switch to this mode. When unplug and plug adapter, power on again, the volume value will stay at 15.
