Our customer sent us an iPhone 6S. His iPhone had accidentally entered the water, and then he found that he could not enter the fingerprint, the recorder could not record, and the audio device could not be found. How to repair this fault?

Use the iPhone Open Tool Kit to disassemble the machine and observe the water on the top. Disassemble and find that the components on the right audio and fingerprint IC are severely corroded. We use the mini scissors to cut the shield for further inspection.

Remove the corroded fingerprint IC U4040 , capacitor C4040 C4043 and resistor R4041 then clean the components. The fingerprint function recover norma when test. Next, I will deal with the problem of sending messages. The audio chip U3500 looks very clean, but it is more safe to remove the chip, and we can test the value of pin by the way.

This is a main power supply for the audio chip. The disconnection means that the audio won't work properly. When test C3603, C3601 with digital multimeter, the resistance value is infinite, and when measure C3603, and the M7 pin of U3500 is connect .

Therefore, the audio main power supply PP_VCC_MAIN is disconnected resulted in no 4V power supply, just need to solder a jump wire from other places. It will be fine soldering a wire to the C3603 or C3601 nearest C3600.

Last , install the iPhone , this repair work finished successfully!