Detail Way for Repair iPhone 7P Boot Failure

According to our ever experience, the fault related with boot failure, usually it was caused by the control IC. 

Anyway, we need to test the current and voltage, then get the final result.

First step we need to connect it to DC power supply with iPhone lightning cable to test the iPhone charging current, the current jumps around 200 mA, not stable. The computer can't identify the iPhone when it is connected, and it doesn't boot.

Nest we need to disassemble iPhone to detect. Use phone opening tools to tear down the iPhone, and then remove the iPhone motherboard. Measure the iPhone motherboard with Fluke 15B+ Digital Multimeter, there is no current, which means no leakage. Trigger it and it shows large current, the current up to 1.9A. Now, apply some rosin on iPhone logic board, and then use QUICK 861DW hot air rework station to heat it, it's turning white.

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It's frustrating to see this, did the iPhone main power break down? Open the WUXINJI Dongle to check iPhone bitmap, we found the iPhone Nand flash power also was in the hot spot, first we need to measure the iPhone Nand flash to check if it is short circuit. After measurement, the iPhone Nand flash is short circuit.

 

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Now, scrape out the iPhone Nand flash around the tape of the power supply large capacitor, and then apply rosin on it, adjust the ammeter to 3 V and heating this circuit by QUICK 861DW hot air rework station, this capacitor is short circuit, remove it.

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After finishing the last step, we test it again, get the normal current and voltage value, boot it,  the phone back to normal.