I have a 2005 C320. The other day, I suddenly could not power on my radio. The screen is blank and the CD slot won't take a CD either. It was working fine all along. All the other electrical items in the dashboard and everywhere else are working fine. This is the original radio that came with the car when i got it ( brand new). I took it to my Mercedes dealer thinking it might be a quick check and quick fix and they want me to leave the car so they can run all these tests and take the radio out if need be. I am afraid they will say it's a big cost and maybe it really isn't. Can someone advise me as to what I should check first to trouble shoot the problem? I reviewed the big manual and it does not give that information. Could it be a fuse? Where is the fuse box for the radio and what would a bad fuse look like? Thank you kindly.