The other day I drove my 2002, A6 3.0 and the radio, cd, and tape player worked fine. I tune the car off and left for about one hour. When I came back, I noticed that the lights on the head unit were on (no other lights in the dash were on). I turned on the car and everything worked fine. However, the radio will not turn on. Again, the lights on the head unit are all on and will not turn off when the ignition is turned off and key removed. The lights have been on continuously for 3 days now.Any ideas about what might be the problems? Thanks in advance for your consideration.

 

The radio head unit is bad. Or it magically coded itself not to turn off.

 

I would first pull the radio fuse out to see if the radio resets, if not I would check the connections behind the radio or the power source under your drivers side kick panel.