I had this problem and managed to fix it. The issue seemed to be with a set of contacts on the new digitizer, they had a piece of the orangey tape over them, which i removed. Do not remove this. On the original, broken one, it had black fabric tape over the copper contacts. The contacts are to the left of the home button when looking at the back of the digitizer, they are both on the home button ribbon cable, one is rectangular and one is square. I put standard electrical tape over both of these and it appears to have fixed the problem.