Can anyone help?

I have an Alpine (Sat Nav; TV, etc) - (actually in a Rover 75 - I understand that it is the same as in an X5) and the AM/FM selector is not working and is stuck on AM. I can't change the channels on AM or switch to FM at all

Anybody had this problem and fixed it or know what the problem could be? - everything else is working fine.

Cheers