I took my 2007 R56 non turbo on a long drive Saturday. Toward the end of the drive the stereo started making a staccato sound with nothing else no matter what channel or on auxiliary. The next day the stereo worked normally (except that FM has never worked since I got it). This morning on the way to work the stereo worked for 30 minutes then suddenly no sound. The display (which is dim when hot but works when cold) continued to work. After a couple of minutes I smelled a tuned electrical smell. Maybe I need a new stereo? I wonder why I didn't blow a fuse.

Thanks for any insight.