See also:

Registering a portable player
Select “Pair Audio Player (Pair Audio)” using a voice command or the “TUNE/SEL” knob, and perform the procedure for registering a portable player. ...

Battery
Check the battery as follows:  - Battery exterior Make sure that the battery terminals are not corroded and that there are no loose connections, cracks, or loose clamps. 1. Terminals 2. H ...

Adjusting sound quality and volume balance
Press the “TUNE/SEL” knob to enter iPod menu mode. Pressing the “TUNE/SEL” knob changes sound modes.  - About iPod • Apple is not responsible for the operation of this device o ...