Where is the reulator on iPhone

Douglas Browning you want to start by checking 3 inductors. For that, of course, you need a multimeter, or at least an ohm meter, to check for continuity. I hate to refer to those as fuses, but they most certainly control part of the charging circuit. First one is reference designator L3, it is a FERR-120-OHM-1.5A inductor. L4, right below it , has the identical value. Next would be the charger inductor L28 2.2UH-1.8A-155MOHM. All of these are pretty much available at mouser. com or digikey.com. Check the Diode D604, located just above L28. U5 PMIC is the IC in green on this image. Check all components as outlined in the schematic part.