iPhone 6 proximity sensor not working, what to do?

Recently, a customer complained that the his iPhone 6 battery is undurable and the current is high at the moment of turning on. CPU is hot and screen won’t turn off during calls. According to the customer's description, Vipprog wrote a repair wizard.

First, we start on screen won’t turn off during calls. Use multimeter to measure the diode data to ground of front camera socket J1111. The diode data to ground of pin 23 towards sensor power supply PP3V0_PROX_CONN is at the low end which is over 260. While the normal one is about 500. The J1111 pins definition is shown in picture 1-1.

1-1

Second, checking the iPhone bitmap and we know the power supply of PP3V0_PROX_CONN is outputted by power chip. Its power supply passes filter capacitor, as shown in picture 1-2, 3 .

1-2

1-3

Third, Replace the power chip and measure its diode data to ground. The data is still the same as before. Thus we can exclude the case of damaged power chip and continue to check the components on power supply circuit of PP3V0_PROX_CONN, finding that the capacitor C1114 is getting dark. So we remove it.

Finally, measure diode data to ground of power supply circuit of PP3V0_PROX_CONN, and the data is normal. Assemble the iPhone and test for a whole, everything is fine.