First check to make sure the underlying cause is not a swollen battery or some other mechanical fault, and fix said fault if found. Reattaching the screen requires a strong adhesive that will not harden and become brittle. I have had success with B-7000 (ordered from amazon). Be aware it is a very vaporous compound, so be sure to use safely -- well ventilated area and avoid contact with the various parts of your body.

I replaced the screen unit but the home button wouldn't work. I replaced the home button and it still won't work.

Anybody have any suggestions?