Hello from Romania!
I own a AVIC Z2 and I have this problem - I insert a dvd, the parking brake is applied, the sound from the DVD menu starts but there is only a black screen and the unit menu (the arrows and enter button etc). Tha DVD is an original one that worked on this unit in the past. I have replaced my touch screen after the old one died, and now I have this problem. Thank you in advance!