Repair iPhone 6 cannot be turn on, case 1

There are many reasons to cause the iPhone 6 cannot be turn on. My friend's iPhone 6 suddenly  cannot be turn on, after triggering it on, the turn on current is 70mA. My friend used iTunes to root it, but the root did not pass and iTunes reported error 4014, and he have no idea what to do. So the technical of vipprog repairs the iPhone 6. Here's the solution.

My friend used hot airgun to heat CPU. When connect computer to root, computer reports error 4014. In general, error 4014 suggests that CPU, Temporary Storage is more or less faulty or the power supply circuits are faulty. After removing the motherboard, we find that around the shield cover of motor drive chip U1400 there is some erosion mark, as shown in picture 1-1.

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Then, we removing the shield cover, we can see that U1400 is eroded. Picture 1-2 shows erosion situation of the enlarged motor drive chip U1400.

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Finally, clean the eroded places and replace U1400. Now iPhone can be turned on normally. The motor drive chip U1400 in Schematics Circuit Diagrams is shown in picture 1-3.

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Here are some summary: The damaged U1400 leads to the poor working condition of I2C bus and computer reports error 4014.