Chosen Solution
Probably a stupid question, but, does the 8 Plus need absolutely everything connected to the board for it to boot up? I know some earlier models don’t. Otherwise, is there any other parts I could replace other than screen and battery, to try get it to turn on? Also, with the home buttons, what is it that pairs them with the motherboards? I have the original button, with no flex cables. So would I be able to get a repair shop to put new cables onto this button, or is that not possible? If that fails, then I’m just going to send it to a shop that does micro soldering and can have a good look at it.
I’ve seen iPhones turn on without the home button, WiFi/Bluetooth antenna, or cameras. I don’t know what it is the pairs the home button with the logic board, but it sounds like the only solution for you is to get it replaced by Apple or an AASP (Apple Authorized Service Provider).
