Ways to repair iPhone 5s suddenly turns black and won't turn on

Nowadays, i believed that most of people like to play the phone before sleep, that's what i am. But, have you ever met the phone 5s suddenly turns black and cannot be turn on? If you have met, i think you will be insomnia. That is a bad thing. Now, we can find the reason and get the solution to fix it.

First, use an adjustable power supply to charge it and charger shows 4.28 A current flow (picture 1-1), which is an obvious shout circuit. Use multimter to measure the diode data to ground of battery interface, which is normal. We continue to measure and find that the main power supply PP_VCC_MAIN is short circuit to ground.

1-1

Second, observing under microscope, we find no abnormality on the surface of capacitors on the circuits connected with PP_VCC_MAIN. We use burn-in method to check the faulty points, using an electric soldering iron to light rosin on the circuits. We find a capacitor under CPU is extremely hot and it burn out the rosin. The capacitor’s color changes from white to transparent, as shown in picture 1-2. The discolored capacitor is shown in picture 1-3.

1-2

1-3

Third, After checking the circuit diagram, we know that the location number of short circuit capacitor is C358, as shown in picture 1-4.

1-4

Fourth, Use hot air gun to remove C358 and use multimter to measure the diode data to ground of the two ends of C358, which is 0, as shown in picture 1-5.

1-5

Finally, after removing the capacitor, measure the diode data to ground of PP_VCC_MAIN, which is normal. Plug the adjustable power supply and the standby is normal. Triggering it on, the current change is normal. Assemble it on iPhone and test other functions, all is fine, the iPhone 5s can back to normal work.