As we know, the iPhone gets into recovery mode after inserting the iPhone lightning cable, there's probably a system problem. However, this iPhone XS Max has no response after pressing the power button, and it gets into recovery mode till we insert the iPhone lightning cable, so first we need to check the iPhone power button.
Use screwdriver to remove the screws at the bottom of the iPhone screen, put the iPhone XS Max on the CPB screen separator, and then use screen sucker to open the screen. Disconnect the iPhone battery, and then remove the iPhone XS Max display screen, take out the iPhone XS Max motherboard.
Measuring the iPhone XS Max motherboard with a DC power supply, and using tweezers to trigger the iPhone XS Max motherboard, we found there was no current reaction, which meant the problem was on the iPhone motherboard.
Use Fluke 17B+ digital multimeter to measure resistance value for the iPhone power button socket, the resistance value measured is 103, while the normal value should be hundreds, which is abnormal.
Observing the iPhone XS Max motherboard under a Trinocular Microscope, no abnormal phenomena were found on this side of the iPhone power button socket.
Login to the WUXINJI account to check iPhone XS Max schematic diagram, we can see that J4300 passes through an anti-static diode DZ4310 and then passes through the R4310 resistor and a C4310 filter capacitor, final reach to the main power chip. So now we suspected that it's the problem of the anti-static diode DZ4310.
Use QUICK TS1200A soldering iron to remove it directly, clean it with the brush, and then use a digital multimeter to measure it again, now the resistance value of the iPhone power button socket is normal.
Assemble the iPhone XS Max, press the power button, the Apple logo appears normally, and then it gets into the IOS system successfully.