The answers about the creased digitizer flex and taping the gold contact areas are all definite fixes for this. Let me add one more that I didn't notice until I swapped a digitizer 3 times on an iPad mini. The digitizer cable end has a piece soldered on where you plug it into the motherboard. The bottom of that piece that is soldered on usually has black or clear yellow Kapton tape. Sometimes when removing the broken one, the black adhesive on the case itself comes up. If your digitizer does not have black or clear yellow Kapton tape, then the solder points on the bottom of the cable will make contact with the iPad housing and cause this issue. I was at the end of my rope with this iPad before I figured this out. If this isn't the case for you, I hope it helps someone else.