Failure is relatively rare (apart from physical damage!) and as the unit opens and closes, the fuse is not broken.
I have seen backlight failure (so you can see the picture if you look really carefully, but nothing lit up).
They are expensive items though :-(
It could of course be the cable between COMAND and the screen, or COMAND not outputting anything (i.e don't go spend £££ on a new screen until you know that is the fault)
Richard