A1534 MacBook 12" 820-00045 - PP5V1_S4SW is missing


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I have 12 inch MacBook A1543 Is not powering on. I started measuring the power rails and I've noticed that I'm missing PP5V1_S4SW. Also U7100 is heating up as hell, and the other strange thing is on pin 56 of U7100 the PPVIN_G3H_P3V3G3H Is around 20V and according to the schematics should be 8.6V. This is my first time working on MacBook 12 inch so I have no idea if this computer can power up without battery or not, also there is not fan to indicate on state and no chime. Makes is really difficult to troubleshoot. Any ideas?


Yes they power on without battery. U7100 heating up is worrying, probably dead to start with. What is PPBUS and PPDCIN voltage?