This iPhone 7P get boot failure after dropping, press the iPhone power
button, the iPhone has no response, in a word, the iPhone 7 plus won't
turn on. We need to fix it.
Use phone disassembling tools to disassemble the iPhoen 7P, remove the iPhone display screen, disconnect the battery, and then take out the iPhone 7P motherboard.
Use UNI-T UTP3305 DC power supply to measure the iPhone 7P motherboard , trigger it, the current up to 60mA and then downs to 0, the current jumps like this over and over again, which is abnormal.
Use digital multimeter to measure the relevant voltage for the RAM, they all normal.
As we know, for the drop-damaged iPhone, the iPhone CPU virtual welding is more likely. Put the iPhone motherboard on the PCB holder fixture, and then put it under a Trinocular Microscope.
Use BGA graver blade to remove the black glue around the iPhone CPU to check if the iPhone CPU is virtual welding, but it's normal.
Based on our experience, the RAM for drop-damaged iPhone 7P is easy to short, let's remove the iPhone CPU, after removing CPU, we found the solder pad missing some pins.
Use JBC CD-2SHE soldering iron to clean the solder pad, and then solder the missing pins. After handling the solder pad well, install the iPhone CPU back to the motherboard.
Now measure the iPhone 7P motherboard with UNI-T UTP3305 DC power supply, the current tested is normal.
Install the iPhone 7 Plus, press the power button, the iPhone 7 plus is turned on successfully.
Use phone disassembling tools to disassemble the iPhoen 7P, remove the iPhone display screen, disconnect the battery, and then take out the iPhone 7P motherboard.
Use UNI-T UTP3305 DC power supply to measure the iPhone 7P motherboard , trigger it, the current up to 60mA and then downs to 0, the current jumps like this over and over again, which is abnormal.
Use digital multimeter to measure the relevant voltage for the RAM, they all normal.
As we know, for the drop-damaged iPhone, the iPhone CPU virtual welding is more likely. Put the iPhone motherboard on the PCB holder fixture, and then put it under a Trinocular Microscope.
Use BGA graver blade to remove the black glue around the iPhone CPU to check if the iPhone CPU is virtual welding, but it's normal.
Based on our experience, the RAM for drop-damaged iPhone 7P is easy to short, let's remove the iPhone CPU, after removing CPU, we found the solder pad missing some pins.
Use JBC CD-2SHE soldering iron to clean the solder pad, and then solder the missing pins. After handling the solder pad well, install the iPhone CPU back to the motherboard.
Now measure the iPhone 7P motherboard with UNI-T UTP3305 DC power supply, the current tested is normal.
Install the iPhone 7 Plus, press the power button, the iPhone 7 plus is turned on successfully.
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