sudomod

I have 2 GBA games loaded on my MintyPi. Both exhibit the same behavior. A few minutes into game play 80% of the right side of the screen goes black. The game is still playing and there is a small stripe of normal screen on the left side. When I push the retropie button (bottom right under the power button) the retropie menu appears full screen normal. When I switch back to the game it is still 80% black.

Anyone know a solution?

I've attached 2 photos.

Thanks,
Silversmith