iPhone 7 Black Screen Repair
How to Repair iPhone 7 Black Screen
The iPhone 7 starts with a black screen or no display, but the boot current is normal. Screen replacements also don't solve the problem. We can draw the conclusion that the backlight circuit of the logic board is out of order.
1:Disconnect the phone and disconnect the battery. Connect the phone to dc power. The boot current is normally displayed, but the phone is not.
2:Disconnect the power and remove the display. Replace the display component. Connect the phone to the dc power supply and power it. The phone still can't display.
3:Remove the logic board. Testing ground resistance of J4502 - normal. This indicates that the backlight circuit is also normal. However, the backlight signal is directly connected to the backlight IC U3701.
4:Using BGA Paste Flux, remove backlight IC U3701 with a hot air gun.
5:Clean the jar with a soldering iron, then clean it again with a PCB cleaner.
6:BGA Paste Flux. Align the backlight IC U3701 to the correct position and weld with the hot air gun.
7:After the logic board cools, clean it with a PCB cleaner.
8:After assembling the phone for testing, the fault has been cleared.
Replacement for iPhone 7 lcd Screen
