MMI screen went absolutely blank on an 04 A8 and nothing I've done brings any activity on the screen. CD/Radio/Nav etc. do not work. I tried to hold the sound button down to shut MMI down with no success (including the three button reset option). The screen does not retract when you stop the engine either.

Any ideas much appreciated.I'm really tired of taking this baby to Audi shop.

 

The A8 uses a fiber optic loop for the radio system. There is a total of 8 componets on the fiber optic loop, if one of these malfunction or if the fiber optic wire gets cut or pinchedNONE of the 8 componets will work.
You HAVE to take it to the dealer, i can guarantee you no back yard mechanic knows how to fix/diagnose this kind of problem.

 

Thank you for the reply auditech79

 

Could it be possible that the same thing happen again ... apperantly it is ...

 

If the MMI completely turned off again on you thats probably what happened. What was the fix the first time?