820-01814-a

[shlom]

Hello
working on a board 820-01814-a from a1990 machine.

the mac is dead, does not charge or power on..

while checking with usb c measuring tool on the charger
it is drawing 5.17V and 0.01A

took out the logicboard, looks very clean, missing PPbus_G3H
and also missing every other power rail, actually can't seem to find any working power rail...

any advice on how to move forward?
any common issue, missing ppbus_g3h with theses boards is worth checking?

on diode mode i get direct short to ground on PPbus_G3H

i have two in exact same condition \ issue..

please you adsive..

thanks.

 

[2informaticos]

Post the exact ohm resistance to ground on PPBUS_G3H; switch to ohm scale.
Compare with the value on the big coils; pay atention to CPU and GPU coils.

 

[2informaticos]

Lift mentioned coils one side (one by one) and check if short disappears from PPBUS_G3H.