I went to my dealer and buy 3 10w, 3 15w and 3 20w fuses because I didn't know which was which. Then I found the slot for the radio using the panel I pulled out and replaced the radio with the single 20w fuse and it works!!

Thanks guys!

 

I am having this same problem. I have checked all the fuses. Whenever the fuse for the radio is put back in it makes a sound like the cds were getting switched around or stuck. The display doesn't light up or anything. it is just dead. I have a 04 a4 b6 with the audi symphony 6cd in dash changer.