I have never seen that message on a Display, so I made a call and got the same answer I was thinking about but wanted to make sure. Under the Display you should see two screws holding it on to the phone base, unscrew them and lift the display and make sure the Display ribbon cable is plugged in all the way in on the phone board, unplug it and re-plug it back in to be sure. That should cure it.

Russ runs a local service and private tech center.

[Linked Image from sundance-communications.com][/url]