Chosen Solution
Hi. So i recently opened my iPhone 8 Plus to replace my battery. Before I opened it up, the touch id was already not working and the home button was working intermittently but the 3d touch and normal display touch was working fine. However, after opening it up and reconnecting the flex cables, the touch only works if the home button flex cable is not attached. Once i attach the home button flex cable, the home button starts working but touch stops. I have to mention that the home button flex cable also seems very loose and I have to attach the metal bracket to keep it in place. What on earth is going on?
The most common cause for this problem on the 8 plus is a stretched home button connector. This happens after trying to fit a 7 plus screen in the past. There are four ground pins on the logic board home button connector which are located on the ends. I usually find the ones on the (right) have been pushed into the plastic and need to be pulled out and the rest of the connector squeezed in with tweezers. To pull the ground pins out you will have to use magnification and a tiny utensil. I usually use 0.01mm wire.
