'98 540i --What went wrong with CD player/RADIO?>

[seths540]

I've had this car 1 week now
BMW 540i Photo Gallery by Seth Klette at pbase.com
Last night had the nav system on, OBC was working as normal, I was listening to a track off cd #6 in the changer. I had tried to "chapter up" and all of a sudden my radio, cd, etc does not work. My OBC and NAV system works fine, but when I press radio, mode, fm, am, weather, etc nothing happens, the car doesn't even act like I pushed a button at all, DSP is no longer a display item on the OBC menu. So It looks like out of nowhere, while driving, my cd player/tape/radio decided not to work. I can push steering wheel buttons, physical buttons on radio, etc. The system never asked me for any unlock code, etc. I pulled over and turned off car, pulled out cd changer magazine, did everything i could think of and nothing happend. I just bought this used 1 week ago, previous owner had it 3 months...showed it to him, he had no idea... is this a common problem?? I miss my radio and CD's...what went wrong???