IMHO
that sounds like pressure on the screen.
liquid crystal does that when there's something pushing on it.
try taking out the foam padding behind the screen.

Do you think that there might be some kind of intermittent connection in the header for the front board ribbon cable?

hi fellows,

i just wanted to mod one my many DMG-01 but have a weird issue with the screen.
The DMG was never opened before and has horizontal lines appearing and disappearing, like there is an electrical interference.
I opened it to install a backlight and looked at the ribbon cables, all in good shape. I switched the caps out on the front pcb, but hasn't changed anything.

Has anyone had such an issue before and knows how to deal with it?
Remember, it isn't the normal horizontal line issue, cause i can set the screen contrast to black and there aren't any lines appearing, only interference lines on normal contrast, like the the herz lines on an old tv sceen.