new lexus owner

Good afternoon I am looking for some advice. I currently own a 1999 IS200 sport with the pop up Satellite Navigation, over the last few months the colour in the screen has been coming and going, from colour to just green (display still usable), usually on bumps in the road, so I assumed it was a connection. It has now stopped displaying anything. The buttons on the dash still open & close and tilt the screen etc but no display. Can anybody help? :zee: