Smartbook 141 C4 not charging and only works on battery

[PopcornMobo]

Okay so i found this Smartbook 141 C4 in the e-waste and it seemed a little too nice to just throw away.
The problem comes down to it not being able to charge or work at all on the DC input.
I don't know if this laptop is supposed to work on DC with the battery unplugged but it doesn't regardless.
I don't have a charger for it but google says it's 5V 4A and i can do that with an ATX PSU no problem. Alas, 5V on the input does nothing.
So i charged the battery with my bench supply at 2A for a couple hours and it seems to have taken some charge.
Enough to power on and allow me to play around with it a little.
With a semi-charged battery the ATX PSU shuts down as soon as it's plugged in, that's because the battery voltage is being back-fed into the charging connector, which is weird.
The back-fed voltage is 1V lower than the battery voltage so i'm guessing it might be passing through two diodes and getting to the output, i think?
Would be great to find a schematic, because right now i'm sort of shooting in the dark a bit because the board is very small and poking around hasn't shown me yet where this voltage is being allowed to pass through.
Any ideas, though?
The battery is a two cell so there has to be a boost converter to increase the voltage, instead of the more traditional buck regulator.
Which so far seems to be the 2R2 inductor and the stuff around it next to the battery connector.
But as i mentioned i can't quite find how this gets it's voltage, but i'll keep looking nonetheless.

Edit: god dammit did i just post this in the wrong section? Sorry.

[PopcornMobo]

Re: Smartbook 141 C4 not charging and only works on battery

So as it turns out the bad MOSFET was all that was wrong.
Internet said it takes 5V 4A input but in reality the input has to be 12V.
I found this out through the battery charger IC datasheet, which is here:
https://cdn.badcaps-static.com/pdfs/...0d530c6758.pdf
As it turns out ACDET pin needs at least 2.4V to turn on and at 5V it would get only around 1V.
But at 12V it would get 2.5V, basically confirming the fact that it needs 12V on the input.
So i switched the input voltage to 12V ant the charging LED came on.
The laptop now takes charge and shows it on the screen.

Edit: Oh and the charger IC uses a buck converter to charge the battery, so there ain't no way it would boost 5V to whatever the 2S pack needs to charge. Case closed.