Chosen Solution
I got a iphone 6s which doesn’t turn on. I bought a u4500 ic from aliexpress and tried to replace the one. It seems to be ok until the apple mark came out. But the screen didn’t change. Just apple mark. reboot reboot reboot again. If i rettach U4500, it would be OK. So I reattached it. And then my iphone 6s didn’t turn on. http://cafeptthumb2.phinf.naver.net/MjAx… Please see my iphone’s screenshot. Could it survive?
Judging from your picture, the pads under U4500 need to be cleaned up properly before trying to install a new Tristar. Remove the old solder, tin it with new, preferably leaded solder and install a new Tristar. If you were to put a Tristar on that messy board, it is impossible it will work.
