See also:

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 ...

Chassis lubrication
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Taking out the jack
Remove the cover. Unhook the rubber band and take out the jack. 1. For loosening 2. For tightening   ...