Horizontal lines at bottom 1/4 of screen with some duplication

Hi

I have my son's iPad mini which has fine horizontal lines at bottom 1/4 (approx.) of screen. It also partially ghosts some of the top of the screen over the bottom area where the horizontal lines are flickering.

It is possible it has been dropped however I do not believe there would be water damage. It has a Thule complete covered case so I thought that may have provided some protection against a drop.

Any suggestions appreciated. I was an electronics technician for a radio station in my earlier days so have a fair ability, with instruction, to fault find and subsequently repair if economical.

Thanks

Tim