Asus X550c - BQ24725A - low ACdrv signal

[ktmmotocross]

Hello.
Have this laptop Asus x550c that wont switch dcline mosfets because of low ACdrv signal/0.93V/. ACdet=3V,ACOK=3V,VCC=19V. Looks like ic's/BQ24725A/ charger pump for ACdrv is broken but i change it and looks the same.

How to get high acdrv signal?

[meritosari]

Re: Asus X550c - BQ24725A - low ACdrv signal

I think you should try to replace new mosfet for AC_FET and BAT_FET

[ktmmotocross]

Re: Asus X550c - BQ24725A - low ACdrv signal

i remove acfet and test it. it is good

i read in datasheet that Vacdrv=Vcmsrc+6V but i have Vcmsrc=0.93V

[meritosari]

Re: Asus X550c - BQ24725A - low ACdrv signal

yes if you have the test results are not short, but in my opinion, gate charge problematic. maybe...

[saularciga]

Re: Asus X550c - BQ24725A - low ACdrv signal

posted diagram please

[saularciga]

Re: Asus X550c - BQ24725A - low ACdrv signal

i remove acfet and test it. it is good

i read in datasheet that Vacdrv=Vcmsrc+6V but i have Vcmsrc=0.93V

Is true , In the gate should have 19 vcc + 6V

[saularciga]

Re: Asus X550c - BQ24725A - low ACdrv signal

Check the capacitor near area of mosfets

[meritosari]

Re: Asus X550c - BQ24725A - low ACdrv signal

Hello.
Have this laptop Asus x550c that wont switch dcline mosfets because of low ACdrv signal/0.93V/. ACdet=3V,ACOK=3V,VCC=19V. Looks like ic's/BQ24725A/ charger pump for ACdrv is broken but i change it and looks the same.

How to get high acdrv signal?

acdet a little high, i think must be arround 2.6v so check resistor first

[ktmmotocross]

Re: Asus X550c - BQ24725A - low ACdrv signal

acdet must be 2.4-3.15v

[dycc]

Re: Asus X550c - BQ24725A - low ACdrv signal

replace mosfet as metitosari said . they might seem good if you check, but can have gate issue

[ktmmotocross]

Re: Asus X550c - BQ24725A - low ACdrv signal

what is "gate issue", i test it with multimeter and works fine

[Esse]

Re: Asus X550c - BQ24725A - low ACdrv signal

dycc,what is it the gate issue

[whaldsz]

Re: Asus X550c - BQ24725A - low ACdrv signal

Could you check the resistance to GROUND of ACDRV and CMSRC pin?