I take it the original screen broke from a fall? Perhaps more went wrong and something ELSE broke also? Other than dissembling and then installing the screen again, you might just have to give with it. We talking just a few dead pixels or major black spots?
OR do you mean there are areas where it won't respond to touch? If so then for sure it sounds like more may be wrong with the device. Might be time to cut and run and replace it. Believe it or not Gazelle will actually buy broken iPads and offer you SOMETHING. I got 55 dollars for my broken iPad air 1. (the offer was 40, but upon inspection they raised it)