See also:

Loss of the remote controls
Lost remote controls can be blocked by your service center. ...

Resetting the tone settings
All tone settings can be reset to the default setting. 1. "CD/Multimedia", "Radio" or "Settings" 2. "Tone" 3. "Reset" ...

Maintenance
The battery is maintenance-free, i.e., the electrolyte will last for the life of the battery. Your service center will be glad to advise you on questions regarding the battery. ...