Your display may be dead for the top. You should pop the radio out just in case to make sure all the connections are in, its possible someone took a parrot or other system out and forgot to reconnect all the wires.
Just bought a 2009 Tribeca with same issue...Short story, I've removed the display, disconnect and reconnect it, and noticed that if I move the socket it will show the radio station/ cd playing... I've put everything back and it works. Probably one of the pins in the socket is dirty or doesn't connect like it should. Hope this is usefull for somebody before buying a new display.
My 2009 Tribeca has the same issue shown in @Rising_Sun's photo. I have noticed that when turning on the car the top section DOES display (I think it says Welcome), so I know the display itself isn't bad. The display is very intermittent on my Tribeca, most of the time it doesn't display. Now I need to get to the connectors and see if there's a connection issue.
From time to time, mine shows ERR, doesn't bother me too much, cause after a slap it gets back to normal . Anyway, more than a year ago I went to a scrap yard and got myself a spare display, just in case.