i have a 99 audi a4 with the audi concert system and 6disc changer. the 6 disc changer didnt work so i replaced it and when i installed it, i pressed the eject button to get the magazine out and nothing happened. so i go to the front of the car and now the whole system doesnt work, turning it on and off with the center knob does nothing, and the lights arent coming on. i checked all the fuses on the driver side panel and all of them were good. dunno what happened.. help!