I got a popcorn 110 secondhand that behaved in a similar fashion and eventually found the output had been set for 1080...trouble was my hd TV I had at that time didn't go that high.
Eventually got it right when I connected it to a suitable TV and changed the output setting.
I was never able to reset it (from memory)as the reset required you to see the menu...not such a smart idea of the makers.
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