Loppyshing

I've searched around and can't find anyone that has a solution to this problem (that didn't require replacing the screen): the multi-function display on my car is receiving power, and registers touch commands, but doesn't display anything but varying shades of black/gray. I never see a start up screen or anything.

I've unplugged the battery, checked fuses, and tried holding the 'display' button while flicking the lights on and off, and the only progress I've made is that the 'display' & light trick gets the screen to show a line sometimes. I haven't yet tried messed with the navigation unit in the trunk.

I just bought the car from a guy who originally had the digitizer issue that everyone else has, and replaced the screen. The new screen worked normally for a short time, and then it went blank, and hasn't changed.

Does anyone have a solution to this, or maybe some ideas as to what I should try? Thanks!