I did nothing but this time when I put the connector in I get 20.25 V and 0.5 A. One fan is spinning, the other is intermittently trying to spin. No chime, no display.

The following components are getting hot,

2R7
R47
U8160656 (Intel chip)
U810C656 (Intel chip)

Thank you for posting this. There's a lot of new stuff in here and I will have to research more in order to understand all the terms but I will that there is enough info here to help me....

Hi!

First post here...

MacBook Pro A1989 (820-00850-A) with liquid damage showing 5V.

I clean the board with alcohol and I get 20V. Fans spin but no chime or image.

I then check the board with a thermal camera and see a component, Q7030, that is hot. I clean extra around this area and now I'm back to 5V.

So... that means it's time to learn how to use schematics and boardview and what I've learned so far is that PPBUS_G3H is the "always on" power mode.

I've checked multiple components pertaining to PPBUS_G3H...

Hey guys,

I'm a one man repair shop in Sweden recently got into soldering and trying to learn how to repair Apple boards.

Looking forward to learning