I have an iPhone 6 plus, facing an issue like this. The motherboard is damaged and it can’t be replaced as they’re not available here in my country. Anyway changed those 3 IC’s and mobile started working, I used it for a whole day but then suddenly the screen went dark blue like it doesn’t have charge left and then completely off, didn’t show the battery sign and never turned on back. Then the Technician said that the Processor chip is damaged. Any chances for it to work or any help regarding changing the chip pls?