2004 A8 owner here. My MMI's been acting up.. cuts on and off by itself.. makes weird sounds (kind of like tapping a microphone).. took it to the dealer, says the amplifier needs to be replaced, cost = $1200!! has anyone had this issue?? Any info on used or OEM parts for MMI? Thanks folks.

 

I've got a similar problem with my 2004 A8L. The MMI system resets continually while driving or not. Even with the key out. Only way to make it stop is either unplug one of the computers fiber optic bus cable or unplug their power. Also stops if I unplug the controls at the shifter which aren't on the fiber optic bus. It also will continually power on and off with the screen closed. I've removed the circuit board for every computer in the system and checked for obvious damage (water or over-current). I'm hesitant to start replacing parts, but I can't do any diagnosis because the computers won't stay turned on to connect with my VAGCOM. Any advice? I've tried to loop them out on the fiber optic side also and it doesn't seem to change anything.