My young son recently dropped our black Wii U GamePad and cracked the LCD screen. Needless to say I was not impressed. I was quoted $150AUD repair/$180AUD replacement. So I thought I'd give a go to repair it myself and ordered a new screen and digitizer for $45AUD.
Upon dissembling the unit, I noticed the digitizer and screen were fused together with a thin, black double-sided adhesive tape. I managed to separate the two and also removed the adhesive tape without damaging it and reused it for the new components. There's also a thin black plastic frame stuck to the face of the digitizer with a similar sticky adhesive strip which needs to be separated as well. This frame sits between the GamePad housing and digitizer.
After reassembling the unit all seemed good, but for one small problem. The new digitizer worked in reverse - up was down, left was right. So I tore it apart again, reattached the old digitizer to the new screen, put it back together and bingo! All was good.
WARNING! Tearing and reassembling the controller is not for the feint of heart. It requires a lot of patience, a steady hand and a large magnifying glass. Two of the ZIF connectors are very small and is an exercise in frustration re-inserting the tiny ribbon cables into their respective sockets.