Chosen Solution
Hello all, I got an iphone 5s in that had non working touch. The guy said after flexing it / twissting it once it started to work again - But then stopped after the update to 11.1.1 Naturally I suspected the one of the 2 touch IC’s had a cracked trace/ball/pad under it. I reflew them and the touch started working again - almost. The power off slider - just as it is getting to the end - will freak out. Same if dragging pages from left to right, it will shoot 1-2 pages to the right once that point it touched. I tried a new screen with the same results. Lifted and replaced U12 and U15. No pads lifted or anything. Looked ok to me. Same results. Connector looks ok also. Any ideas where to go from here? Since it was update with a possible touchIC problem… is there some sort of calibration it does during an update for the screen that could have calibrated out of wack? Software issue? Seems more like a hardware one from my knowledge. Thanks and I hope I can get this one solved!
Have you tried an EOM quality screen or an aftermarket? iOS 11 has been very problematic with aftermarket screens but that is mainly with the 6S. As far as I know, there isn’t a calibration that needs to be done. If after replacing the IC’s you have the “exact” same problem, then the IC’s aren’t the issue. One thing that could be happening is a damaged trace, like the M1 pad issue on the 6 Plus. If you see similar looking small traces, they may be microscopically damaged. For example, the VSTM and SENSE lines on SAGE are what constitute the touch grid. If only one of them is bad, you could have a dead zone (vertical or horizontal). The issue with the 6P was that the BSYNC line had the flaky trace, hence causing sync issues between the LCD and Touch - hence no touch.
