I have a 2001 Audi S4 with the Bose Symphony sound system. All worked great until I recently pulled an incredibly bone headed manuever. The car itself is not driven often and subsequently eats batteries every 2 or 3 years. My wife recently tried to start it and the battery was dead. I went to jump start it and connected the positive to negative posts. Obviously not a good thing. Left it there for a few seconds and it heated up quickly with the cables smoking. Recognized my error, removed cables, waited for cables to cool then jumped it and car ran fine except the break light was flashing and the stereo no longer powers up. I checked both fuses and found the anti skid breaking system fuse to be blown but the stereo was fine. Replaced both just to be safe and the break light no longer flashed but stereo is still dead. Any other suggestions for a semi-handy guy? Any idea what type of damage I may have done?

 

Don't know about the 2001 Bose Symphony, but my 2003 Symphony II has a fuse on the backside of the head unit as well. Have you removed the unit to check that?