Asus x442u no power

[Yosua]

Hi friends, I currently have a problem with the Asus X442U mobo no power, the measurement is on
PQ8901
S=19v
d=0v
g=0v

PU8901
ACN=0V
ACP=0V
CMRSC=0V
ACDRV=0V
ACDET=0V
SDA=0V
SCL=0V
REGN=0V
VCC=19V

I've tried to replace both ACFET and charger ic the result is still the same, and I was able to connect the drain to the PQ8901 source with a cable and without the first ACFET, the result is 19v can penetrate up to PRS8901

I hope someone can guide me for this problem, I also included a Boardview for this mobo

[mon2]

Re: Asus x442u no power

Which chip is at PU8901 ?

There are a number of concerns including:

ACDET - often this is a simple resistor based voltage divider and driven by the external power adapter. Why is this signal at 0v ?

The SDA and SCL lines are at 0V. This implies the I2C pull up resistors are not being pulled up to the always on rail. Locate the resistors and then trace back to which ic is the always on rail. Likely a +3v3 rail that is missing here.

Post the details of the IC at PU8901 so we can all review a reference schematic for this part.

[Yosua]

Re: Asus x442u no power

Which chip is at PU8901 ?

There are a number of concerns including:

ACDET - often this is a simple resistor based voltage divider and driven by the external power adapter. Why is this signal at 0v ?

The SDA and SCL lines are at 0V. This implies the I2C pull up resistors are not being pulled up to the always on rail. Locate the resistors and then trace back to which ic is the always on rail. Likely a +3v3 rail that is missing here.

Post the details of the IC at PU8901 so we can all review a reference schematic for this part.

thanks for giving a little of your time to help me bro

This ic has code BQ24780S and I also got the datasheet as attached

[mcplslg123]

Re: Asus x442u no power

Are u sure regn is 0v??If regn is 0V,the ic definitely bad

[Yosua]

Re: Asus x442u no power

Which chip is at PU8901 ?

There are a number of concerns including:

ACDET - often this is a simple resistor based voltage divider and driven by the external power adapter. Why is this signal at 0v ?

The SDA and SCL lines are at 0V. This implies the I2C pull up resistors are not being pulled up to the always on rail. Locate the resistors and then trace back to which ic is the always on rail. Likely a +3v3 rail that is missing here.

Post the details of the IC at PU8901 so we can all review a reference schematic for this part.

after i jumper the acfet 19v appears but the 3v voltage is gone too bro can you guide me?

[Yosua]

Re: Asus x442u no power

Are u sure regn is 0v??If regn is 0V,the ic definitely bad

The ic is new bro..