2000 E430 Bose No Display but still works
 

In my 2000 E430 with the factory Bose stereo, there is no display on the unit's LCD. The heads-up display above the steering wheel shows "Audio Off" at all times. The tape player won't open. The unit still produces quality sound on all speakers and I can change player modes (except tape player) and stations if I guess which button to push. Any idea whats going on?