More than 90% iPhone screen issues can be solved by replacing a new screen, but for an iPhone back light issue it’s a different story.
A smartphone relies on different parts on it to corporate to display properly. These parts include the screen itself, display ICs, CPU, Power supply ICs and all other components that connect all these main components together. There would be display issue even if only one of those components was defective.
iPhone back light issue looks like what the image shows below. There is display on the screen, but because there is no back light it can be hardly seen.
It’s quite a hard work to describe how we do a motherboard repair in details. All this can be boiled down below:
To tackle a motherboard issue, we have both component logic connection schematic and PCB board layout and professional tools that help digging out problematic points and then repair/replace the faulty parts.
Depending on specific cause of this issue, different approaches might be adopted, including soldering rework, jumping wires to reconnect open circuits, faulty components replaced etc.
