Chosen Solution
I have no fan / no power on my MacBook Pro. My MagSafe charger LED is either Orange or Green, but the system doesn’t power up. I don’t have PPBUS_G3H. Does someone have an idea why? U7100: Pin 2 = 16V17-18 = 4.2Ω (normal)27.28 = 20Ω (normal ) F7140 = resistance to ground 1,4Ω ?? UPDATE: PPBUS_S5_HS_COMPUTING is shorted to ground. Pin 2 of C7316 getting hot.
Update (11/22/2017) The HS Line is shorted to ground. I Cent do anything beacuase of The hole in Board.
There is a short to ground on PPBUS_G3H, feel U7100 to see if it is getting hot. If it is not, remove F7140 and see which side the short to ground is located, where PPBUS is created (charging chip side) or system side (anything powered off of this line). Keep in mind this voltage goes to at least one 4 way low ohm resistor, so something from this could be shorting PPBUS_G3H to ground. If you don’t notice any visible damage, try injecting a small amount of voltage on this line and see what gets hot.
If U7100 is getting hot replace it. Fairly common failure
See the pin out of the mag-safe in the diagram on the right hand side of this wiki: https://en.wikipedia.org/wiki/MagSafe
I have the same problem, Only the light sells turns on and does not turn on, it falls short in this part but I cannot locate it in the schematic manual. Can someone help me which part is the image?
