Q5 MMI appears dead

My 2016 Q5's MMI screen and buttons recently went dead. I've tried these three solutions:
1) Verified the fuse is good.
2) Swapped in a new MMI PC card.
3) Swapped in a new MMI LCD screen.

None have had any effect. Any suggestions for #4? Scared to death to take it to local Audi repair due to bad experiences.

Douglas

Without diagnostics it is just guessing... As point 1 I would do an autoscan and check MOST (optical databus/ring) ...