Lowrance X-65 Won't Scroll

[mlsa]

A while back I bought a Lowrance X-65 from a guy off Craig's list.  I mounted it in the console plate on the bow of my boat.  It has the temp and speed gauge and works great...except that it won't pick up anything and scroll.  My first trip with it I just thought I didn't have all the menu's right so I've played around with it some.  Still nothing.  It scrolls in the demonstration setup.

I thought maybe it was the transducer which I have mounted on my trolling motor.  Friday I went fishing and happened to think about my X-49 on the console at the drivers seat.  I made sure it was picking up the bottom and then unplugged it and plugged in the X-65....still nothing.  Everything else works great on this unit.

Any suggestions what it could be?  Or do I need to bite the bullet and buy a new one?

Thanks