A client complains that his iPhone 6 battery is draining quickly, it’s very inconvenient for him. After we check it, we found the iPhone proximity sensor is damaged.
Disassemble the iPhone 6 by JM-P01 Electronics Toolkit, then connect it to DC power supply, when the iPhone is on standby, the current is normal; however, when we boot it, the current directly jumps from 300mA, the normal current should be from 80mA. As shown in picture 11-7-1.
Client said that the phone is not black screen, the flex cable was replaced before but the failure is still existing, it seems that the fault is from sensor. Take out the universal multimeter to measure iPhone 6 motherboard.
When testing 3V power supply on sensor, plate is short circuited to the ground, the power supply goes out of the PMU to the J1111 interface, with a series of capacitors in the middle. The capacitance is distributed in three places: near J1111, the upper left corner of the iPhone audio, and the power supply. These three places are all smoked with rosin flux to check.
The capacitor rosin on the top of the PMU chip is melt, so we pry it out. Now he resistance was restored to normal, and the electric current jumped to normal.
Finally, install the iPhone 6 and test it, now the the proximity sensor is back to normal, and the iPhone 6 battery usage is back to normal now!