iPhone 12 does not turn on for repair

Machine model:iPhone 12

Fault phenomenon: mobile phone does not turn on.

iPhone 12 does not turn on Figure 1.

no booting ance process: press the power on key of the mobile phone, disassemble the machine and connect the no booting ance power supply. It is found that Connect the power supply large current indicates that the main board Short circuit is wrong. Add Colophony (Solder)to VCC on the second end of the main board, and start Current heating test.

It was found that Colophony (Solder)on the surface of an Capacitor melted. After the auto power off capacity was buckled, the two ends of Diode value is normal were Diode value is normal. It was found that the Capacitor was PP_VDD_Main VCC filters Capacitor.

iPhone 12 does not turn on Figure 2.

iPhone 12 does not turn on Figure 3.

Connect the power supply test motherboard is no longer short-circuit current, press the power on key current change, install the motherboard into the machine, turn on the test mobile phone to display normally.