Glitched vertical lines on TI-82 Stats.

A few days ago, I dropped my TI-82 Stats calculator. At the same time, the batteries ran out, so I'm not quite sure which of them caused the problem. Anyways, when I had inserted new batteries, the screen had thick glitched vertical lines that obscure every other character. The "glitched" lines mostly look like a "ladder"-pattern, but there is a thicker line in the middle, what looks like noise to the far left, and there are some missing pixels here and there. It has looked like that since I pressed the graph button (or whatever it's called, I don't have the calculator here right now). Before that, it was an even thicker pattern. Does anyone know what the problem could be and how to fix it?