Audi MMI problem, not powering on, diagnosis and fix for the A4, A5, Q5, S4, S5

The MMI system on our Audi Q5 wouldn't start or power on after jump-starting the car. I tried hard resets, disconnecting the battery and checked the fuses, but it was the tuner that had failed and needed the MOST system bypassing. This shows how I diagnosed, found and solved the issue #audi #car #automotive #carproblems #satnav #carfix #q5