Hi all, ive just bought a 2009 A3 tdi, i noticed that the radio wasnt getting a reception so i took the unit out to make sure the ariel was connected, which it was, but when i put the unit back it was dead, i checked the fuse in the back and when i took it out and put it back in it make a noise so there must be power getting to it, but the whole thing is just dead, no lights, nothing, ive checked the fuses under the bonnet also, any idea guys ?