What caused iPhone 7 black screen

Vipprogrammer is Professional iPhone mobile phone repair tools online shopping mall,we supply iPhone mobile phone all repair parts with for your repair business.

As we all know, the iPhone screen problems have plagued the Apple users, no matter how expensive is. Today, Vip Pro Shop Team will share a phone repair guide to you: “how to fix iPhone 7 shows black screen or no display".

1. Carefully disassemble the iPhone 7 and disconnect the battery. Put iPhone connect to DC power supply, the boot current is normal, but the display screen still black.

2. Carefully disassemble the display assembly, and replace with new one. Once again put iPhone connect to DC power supply and then power up, the boot current displays normally, but iPhone still goes with no display. So, we suspected that this problem is caused by motherboard backlight circuit broke down.

3. Teardown the iPhone, take out the motherboard. Measuring the grounding resistance value of J4502 with multimeter, the data is normal, which shows that the backlight circuit is also normal.

4. Because the backlight signal is connected directly with backlight IC U3701, now we can judge that the backlight IC U3701 broke down.

5. Paint some BGA Paste Flux, take down the backlight IC with Hot Air Gun at 320 degrees. Now, we need to clean the tins, use soldering iron blow it first, and then use PCB Cleaner to clean it again.

6. Paint some BGA Paste Flux again, align the backlight IC in the correct position, and then solder it with Hot Air Rework Station. Cooling the motherboard, and then use PCB Cleaner to clean it.

What a good phone repair looks like smile, assemble the iPhone 7, turn it on and test it, now the iPhone screen was not black, it can display normally.

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