macbook air 2020 820-01958 no boot

[donnos]

Hello,

820-01958 came in with a water damage at the titan ridge area, surrounding area cleared up.
macbook now boots with battery but not charging. 20v when plugged in charger but 20ma. customer took back macbook for data backup, brought back laptop with depleted battery to be fixed.
checked the battery, it is now busted, and won't take a charge. Replaced with new battery but does not boot now. Does not boot without battery installed as well.

here is where things get weird. on the old busted battery. when i plug in charger i get a low battery icon on screen
where do i start?

 

[2informaticos]

So the new battery doesn't even show low battery icon on start?
Can you post PPBUS_G3H with each battery connected?
Do NOT connect the charger.

With only charger connected, post PPBUS_G3H and 3V3_G3H voltage.

 

[donnos]

on the old battery is 0v at the connector but 10.9V at the terminals, guess the battery controller board is dead somehow
on the new battery connector 11.3v ppbus is 11.3v and 3v3_g3h is 3.2V

i want to add as well that the low battery sign does not consistently come up.. sometimes it does, sometimes it does not when i unplug and reinsert charger

 

[2informaticos]

There should still be something affected by liquid.
Check what happens disconnecting trackpad/keyboard.