Bad Arduino or bad 4D display?

I have lost communication with between the controller and display. My components are a Mega 2560 and a 4D Systems capacitive touch display. The display is connected via interface and 5-way cable to a Rev2 Shield on the Mega. The display shows imagery and cycles forms, the Mega compiles and uploads like its suppose to, I use the components to execute continuity test. My problem is, nothing happens when I make a selection on the display. Is there a way to see the display talk to the controller? Is the Mega prone to failure under certain situations? Does the programming need specific language to include or read the display? #IMACARGUY

Thanks in advance!