The Moultrie I40 was the first digital trailcam I owned. I still say they took the best pics of any commercial cam I have ever seen. The screen going out on those is a common problem and it sounds as if yours may be getting ready to die. I'm not sure if you can still get those screens from Moultrie or not but it would probably be worth a try. Good luck.
Blessings........Pastorjim