I have a Concert Stereo in my 2000 A4 avant connected to a DP9060EN CD changer. I switch on the stereo and nothing happens, except the display panel slightly lights up. No error messages or anything. This happened a couple of times, but now it won't come on at all. I have tried reseting the CD changer and replacing the cartridge, but still no joy. ANybody seen this before or got any ideas ?