How I can check what is wrong with logic board?
Hello, i have problem with my iPhone 6 16GB.
Yesterday everything working good, in night it was on charger... And at the morning it wasn't possible turn on. No answer, only black screen. I try too hard reset and connect to PC, but still nothing, only black screen. I have too one iphone 6 icloud lock, i try change logic board, but when you put this logic board to this iphone for parts still no working, when i put icloud lock logic board to this second iphone, it was good. so some issue must be with logic board. But i don't know what next. I don't know how i can check what is wrong with logic board. From outside look normally, nothing wrong. Please help me ... Thanks