Ok so on a mini 1 you’ve checked L2200 & D8228. can you check you have continuity from L8225 -> D8228 -> L2200 -> pins 30 & 32 on J2201 FPC ? Next what is the voltage ? is it just VCC_Main or boosted somewhat ? either way after that i feel your looking at U8100 if all else checks out . Oh and if the voltage is right maybe test a known good lcd Best of luck Hector Hind
In Situation #2 did you use the screen from the first XS rear glass repair ? Either way to me it does sound like you just damaged the FPC connector/cable upon removal. Next one you get for lcd repair make sure to test the touch before removal then test again each step of the way ie pry up the lcd and undo the shields, disconnect the battery then reconnect it and test is touch still working ? ok great next disconnect battery and lcd connectors , reconnect, retest, remove again, place aftermarket one on and test , disconnect , reconnect original lcd and test ect ect Process of elimination will lead us to the answer here :) Update (05/15/2019): Interesting , i must say i’ve only had them in for lcd replacement so havnt’t looked into this much . the next one to come through my store i’ll be sure to test and report back.