820-02020 PPBUS is floating

[Pavel]

Hello,everybody!

I have another Macbook Pro 13 A2338 , Board 820-02020 no power, no liquid damaged

PPBUS_AON is floating constantly like I have shortage .

I've removed the F5200 and have good voltage on C5250

I've tried to inject some volts on this rail , but no current consumption...

In diod mode I have 600 ohm (if red on the ground) and nothing in another way

What's it be?

 

[2informaticos]

3V8_AON pulsing too?
Also check U8100 and U7700 LDOs.

 

[Pavel]

3V8_AON is stable, 3.8 volts
But PPBUS_AON is floating constantly from 7v to 12,3v

 

[2informaticos]

Compare diode mode readings on all power rails with good board, or OpenBoardData reference table.