Raymarine SL70 Radar Display Problem

[aquavit]

We have a Raymarine SL70 radar display unit that turns on and seems to show an accurate radar display, however, the soft keys, cursor,etc. won't work,nor will the interface to the garmin GPS. The 13 pin and 7 pin input cables seem to be inserted tightly at the back of the display. Any ideas on what to check before we spend a bunch of money to send the unit into Raymarine? Thanks for your ideas!