Asus UX303UB charging problem green led blinking

[Fernon@Repair]

Re: Asus UX303UB charging problem green led blinking

ac ok showing 6v.... no power no lied showing solution pls asus x409aj

[mon2]

Re: Asus UX303UB charging problem green led blinking

For this application, the ACOK is pulled up by a resistor to REGN. So we know REGN is a good value of 6V.

This voltage value is used to boost the voltage on the ACDRV pin.

What is the voltage on the ACDRV pin?

After this check, remove all power. Then locate and remove the external resistor (~4k ohms) that will be in series with the ACDRV pin on the charger IC).

After this resistor is removed, what is the voltage of ACDRV pin? If all is ok, it should be ~25 volts = adapter input voltage + REGN voltage.

Confirm it.

[canali]

Re: Asus UX303UB charging problem green led blinking

thanks

[mon2]

Re: Asus UX303UB charging problem green led blinking

With a 19v power adapter as the source, the voltage on pin #28 (VCC) is too low.

There should be a dual common cathode diode to feed power from the adapter or battery. Check the voltage on each pin of this dual diode. If still the voltage you posted, replace it.

Also with no power, check the resistance to ground of this VCC pin. Something is wrong here to drop almost 3 volts.