Asus N752VX not charging

[BugDroid]

hey

I have an Asus Vivobook which runs fine on AC but doesnt charge the battery.
I did try with a new battery too, but issue remains.
the charging power is activated by 2 mosfets and I am pretty sure the mosfets get their signal from a IT8995.
can the chip be verified?

[piernov]

Re: Asus N752VX not charging

Does it run from the "new" battery, AC adapter disconnected?

[BugDroid]

Re: Asus N752VX not charging

Does it run from the "new" battery, AC adapter disconnected?

yes it can. as well as with the old battery. Until its running out of power of course.

Just realized that I put the wrong name of the chip, sorry. The correct name is BQ24780S

[piernov]

Re: Asus N752VX not charging

Does it report the battery percentage properly? What's the voltage on the battery rail with:
1/ AC adapter connected, battery disconnected
2/ AC adapter disconnected, battery connected
3/ AC adapter connected, battery connected

[BugDroid]

Re: Asus N752VX not charging

Does it report the battery percentage properly? What's the voltage on the battery rail with:
1/ AC adapter connected, battery disconnected
2/ AC adapter disconnected, battery connected
3/ AC adapter connected, battery connected

values on the battery connector:

1) 0V
2) 13,8V
3) 13,8V


with no battery connected, windows says no battery detected.
if the battery is connected and somewhat charged, windows reports the correct level. if the charger is connected, windows says charging, but the batt. level never changes


I have 2 identical laptops here. The battery is 100% ok

[piernov]

Re: Asus N752VX not charging

EDIT: double check that both DC-in MOSFETs are not shorted drain/source/gate first.

Ok, maybe a random failure of BQ24780S.
You can either replace it right away and see if it solves the problem, or measure voltage on all its pins to try to find a hint.

[BugDroid]

Re: Asus N752VX not charging

EDIT: double check that both DC-in MOSFETs are not shorted drain/source/gate first.

ok, this is the whole story:
a few backs I had a problem with the LCD which startet to show black lines. After trying to bent the cable to the LCD and the small LCD on the LCD, the laptop wouldn't start anymore and the power supply would disable the DC output when connecting to the laptop. I found out that the 2 DC-in MosFets were shorted. I replaced them (and also the LCD) and the laptop would start again but wouldn't charge the battery anymore.

I realized that the chip has a I2C interface. Is this of any use?