Have you tested your hardware ? HDD or SSD not broken ? RAM not broken ? RAM you could run memtest and see if it gives any error, for HDD you have couple of different ways to test, but i always unplug it, and test it external on an other pc with hdsentinal, some people will tell you even if its at 98% its still good, but even then it could be better to replace it. If you have an other HDD somewhere just test if it works with that one.
Well, i'm guessing the lcd and digitizer are sepperate since its a touchscreen laptop, so i'm guessing you are fine with just replacing the ' touchscreen part'.
Try adding some axtra pressure to the screen so the tape can really stick to it, if that does not work, try adding a little bit of B-7000 and add pressure to the screen.
Did you try take a backup and reset the ipad ? i highly doubt this is a screen problem, more like a software problem, also it could be a defect homebutton in the meaning that it will work but if you click it it wil stay clicked giving you everything to see ( siri and so on )