Disassemble the iPhone 7, remove the iPhone display assembly, disconnect the iPhone battery, and then take it out. First we try to fix it by replacing the iPhone 7 battery. After replacement, the iPhone 7 still won't charge.
Use screwdrivers and LCD suction cup pliers to disassemble the iPhone 7 again, remove the iPhone display assembly. Now we try to fix it by replacing the iPhone tail plug flex cable, however, the iPhone 7 is still not charging.
Put iPhone motherboard on the PCB holder fixture, and then use tweezers to remove the cover shield for the USB IC. Now use QUICK 861DW rework station and tweezers to remove the iPhone USB charge IC, clean the solder pad, and then install a new iPhone USB charge IC to the motherboard.
Use iPhone lightning cable to charge the iPhone 7, after a while, the iPhone 7 power percentage increases properly, the iPhone 7 charge problem has been solved!
Hope we can help you with these tips. If you have a better and more effective solution, pls leave a message in the comment below.