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NO POWER A1707

levi

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I have a macbook pro 2017 touch bar with no power. it had a short circuit on PPDCIN_G3H power rail. C7029 was shorted. replaced it and now i have 20v on the rail up to r7020 . Now my challenge is with PPBUS_G3H. i have 1v on this rail . whereas when running measurements i kno that rail should be 12.6v. which means q7030 and q7040 are not switching to produce the 12.6v. Without charger plugged in i record high impedance on L7030, but with charger i read absolutely ov on L7030 which i know is not normal that's a short circuit. Now I know the best way to address this problem is to change both mosfets and the pwm IC ISL9239 U7000. Any advice on that. And my other problem is with some googling around , i don't seem to find any links to ördering the FDMD8800 mosfets. is there any generic fets like this i can use an equivalence for this FDMD8800 mosfet? Below is a snapshot of the portion of the schematic that i made the troubleshooting from and all the components quoted in this little write up.Thanks a lot already for your replies and support.Capture.PNG
 
Too bad I cannot find the schematic nor board view.
According to your post, I suggest to replace the U7000 and check the resistors also. That should give some different answers. I will try to give more if I can find the boardview and schematic. Other than that it is very limited for finding out the power sequence and switches.
 

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