Hi,
I've had this problem for the last two years. Mine seems to be temperature/humidity related. The display is OK in the hot/dry but is blank in the cold/wet. For example, I was driving last weekend in quite hot weather with the a/c off and the display worked perfectly, prior to that I hadn't seen it since November!
Collective opinion at my work (where we have engineers who work on electronics and displays) is that it's probably a dry joint that reflows when its sufficiently warm. I've had a couple of volunteers to look at it for me but without circuit diagrams and without a ready replacement, I've not been keen to let them play.
Sorry I can't be more help.... It would be nice if someone knows a good replacement that will fill the space and provide reversing camera viewing..?