Asusu vivo book not charging

[koby058]

Hi gentlemens,
I have this vibo book that got a bit of water. After clean up the boarf. It works on adapter and work on battery, but it is not charging.
I have checked first and second mosfet They look fine. Replaced 9241H to a new one but it is still not charging. Battery accept charge directly from power supply.

Can you advice on things that i can check?
Motherboard have no schematic available online.

[mon2]

Share the full measurements of the DC in mosfets. Recently repaired an HP with same issues and the fault was the first DCin mosfet.

Remove all power. Meter in resistance mode.

Test resistance across:

source / drain
source / gate
gate / drain

Post each measurement. Suspecting you have a bad mosfet.

[koby058]

first mosfet
source / drain 290k
source / gate 470k
gate / drain 155m

second mosfet
source / drain 290k
source / gate 400k
gate / drain 2.5m

both are p channle pk5b9ba

[mon2]

gate / drain 155m

Is this correct or should be 155k ohms?

[koby058]

I see that the polarity of the multimeter matters when you change direction

when i probe both mosfets where black prob on drain and red probe on gate

igot 2.2M on both mosfets

what do you think?

[mon2]

See attached. Connect both the power adapter and battery. Carefully measure the voltage to ground of the following pins (more later):

ACOK
DCIN



Datasheet:

[koby058]

Sure

ACOK is 2.99v
DCIN is 18.79v

[mon2]

These voltages look ok.

Remove all power. Meter in resistance mode. Measure the resistance between CSIP and CSIN pins. This is the battery charge current sense loop resistance path. Measure directly at the charger IC pins but without power to the board.

[koby058]

CSIP to CSIN is 2.5 ohms

[mon2]

The resistance looks to be in line. See the evaluation kit for the ISL9241 for guidance on what is most likely copied on your Asus motherboard.

What is the voltage to ground on each pin on the battery connector?

[koby058]

Hi, I will only be there on sunday and i will check that.
I have found out that the laptop only works with battery connected and not charging
I am not sure if the laptop must have a working battery for it to work or it is indicating an issue
I will send the values next week

[koby058]

Hi,
So, when i measured the main power rail i saw the voltage spiking between 13v to 15v so i have figured it is a voltage regulation issue
checking all related mosfet, i found another 2 N channel mosfets and another small one that got a bit of the water damage on the back of the board.
replacing it solve the issue, thanks a lot for the help!