I'm stuck. Working on an 820-3787, 2015 MBP Retina. PPBUS_G3H does not have 12V, only about 2V. I discovered that mosfet Q9330 near the GPU was getting hot. I removed it and sure enough it restored my 12V. However, when I replaced it the short returned. I replaced all three mosfets in the area, Q9330, Q9331, and Q9361. No dice. So I resoldered and eventually replaced U9300. Still no luck. In fact now, even when I remove Q9330, there's a short on PPBUS_G3H. When I send power to it, it draws .2 amps, pin 1 on Q9330 sparks and gets hot, which is the UGATE from U9300, only showing about 1V on it.
U9300 isn't getting the right amount of voltage in, which would cause the gate to not open, but im not too sure why it's not getting the voltage. I think it might be a faulty GPU. Does anyone have any ideas? Someone else had worked on this board before me and I'd rather not waste a ton of time on something I can't fix.
U9300 isn't getting the right amount of voltage in, which would cause the gate to not open, but im not too sure why it's not getting the voltage. I think it might be a faulty GPU. Does anyone have any ideas? Someone else had worked on this board before me and I'd rather not waste a ton of time on something I can't fix.
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