Our course today is about iPhone X touchscreen unresponsive repair.
Press the power button to turn on the phone. The phone turns on normally. Touch screen of the phone is unresponsive.
Turn off the phone and take apart it. Disconnect the battery and remove the display assembly.
Take out the motherboard. The first thing we do is to check the Touch ID FPC connector J5800. Run diode mode measurement of J5800. The measured value of Pin 22 is OL which indicates that Pin 22 relevant circuit has open-circuited.
We can see that there is an inductor FL5893 on the circuit. Let’s start with FL5893.
First, remove sponge around J5800 with tweezers. Run diode mode measurement of Pin 1 and Pin 2 of FL5893. The measured value of the two pins is 0. Judging by the measured value, FL5893 is in normal status.
We can see that the circuit makes its way to the third space PCB. So we need to separate the motherboard to check the third space PCB. Place the motherboard on the specialized Heating Platform. With temperature of the platform reaching 160℃, pick up the upper layer with tweezers.
As you can see, plenty of solder joints on the third space PCB have fallen off. And the motherboard is severely deformed. Judging by this, the motherboard is unrepairable.
Conclusion
iPhone X touchscreen is unresponsive. The first thing we do is to check the Touch ID FPC connector J5800. Run diode mode measurement of J5800. Judging by the measured value, Pin 22 relevant circuit has open-circuited. We can see on the bitmap that the circuit makes its way to the third space PCB. Separate the motherboard and we find that plenty of solder joints on the third space PCB have fallen off. The motherboard is also severely deformed. Judging by this, the motherboard is unrepairable.