Well.. Note that there have been NO repairs available for Touch ID since iPhone 5s, because the sensor and the processor matched one-to-one. I’m not a professional so I don’t exactly know this thing for Air 4, but I’m sure that you can’t replace Touch ID by yourself. I recommend that you go to the Genius Bar.
It’s extremely hard to connect LCD and Button cables. I screwed it up while reconnecting the cables. IF, you want to disassemble this machine by fun, don’t ever try it.
