Malfunction Phenomenon
The phone just can’t be turned on suddenly.
And with a large current once gets connected with the DC power supply.
Troubleshooting
For the issue iPhone 8 Plus Cannot Start Up With a Large Current.
According to the experience of repair, we can find out the fault of the component with the rosin detecting method.
Soak some rosin with soldering iron and then smoke rosin on the surface of the relevant components on PP_VCC_MAIN. Apply a proper power voltage and find the rosin on C2859 melted.
Judging by this, the fault is related to C2859. Because C2859 is a filter capacitor, so we can remove it directly.
After that, got the motherboard mounted and display assembly installed, and test again, all function is normal.
Problem resolved.
Repair tips
For issues like large current once connected with DC power supply
Normally it’s caused by the related power rail which before press power button with some power leakage.
The rosin inspection method or thermal camera detection method is quite easy to find out the shorted components.
And as mentioned, after finding out the shorted component, just replace it or tick it off directly.
(Normally, the filter type capacitor can be ticked off directly)
