Hi, I have a 2000 MY E39 M5 and I have retrofitted a MKIV NAV and 16:9 screen a while back. These have worked for years, but recently, I started getting a full bright white screen.
It looks like this - all phosphors lit:
The radio continues to work and I think the NAV is working, but I can't easily tell since I do not know if I can get it to do anything without seeing what I am doing.
It will go white for a day at a time or so and then sometimes it will be back to working after parking the car for a while. I would really like to solve the problem if anyone has any clues.