"CD Not Available - Insert Nav CD"??

[bpar1713]

The Comand Navigation in my 2000 S320 has started showing "CD Not Available - Insert Nav CD" after a trip to the dealer where the battery may have been disconnected.
It won't eject when pressing the eject button but I can still insert the earlier Nav CD which goes in, gives the same message AND ejects properly.
It's a long trip back to the dealer who says over the phone it was not touched.
Reading all the threads I can find it seems a likely cure is disconnecting / reconnecting power to the unit so I'm hoping someone can tell me the likely cause and, if so, if there is a particular fuse I can pull or if I have to disconnect the battery with all the consequent resetting.
Any suggestions will be most welcome.

 

[ROBGOSTY]

Sounds like your original CD has been pinched, no way could you put your earlier one in as well

 

[television]

Actually on some of these earlier units you can get 2 disc in,,,but if one is ejecting then the other must as well.

I would try a wet cleaner first, there are firms that fix the ejecting and that is just wear and tear

 

[npuk]

Have you first off all established whether or not there is actually a cd in there?