Radio stopped working

In my case, it is tied to my Nav system (I was asking about 'that' one too) (see down below) took it to a stero system expert who said they are tied together. I don't know if you are having problems w/ your nav, but if you are, simply remove nav in trunk and unplug, plug back in (both my radio AND nav are working again) just needed to be 'reset' apparently!! However, there were NO PROMISES they would be continue working, but....so far its been over a week, and they are (knock on wood!)