Need Help with Asus UX305F Mobo, power light on, charger light off, dead laptop

[wilson1002003]

Hi, im working on Asus UX305F. This laptop just suddenly dead out of nowhere. When i plugged the charger (already check the charger was fine with 19v output), the light on power button (in the keyboard) was flashing, the power indicator turn on, the battery charging light off.

I dissambled the laptop, one cell of the battery seems puffy, but i still can get 11v from it, so i assume the battery still usable. tried to unplug the cmos battery and plug it back. still no luck.

tried to do the measuring, i can still get my 19 volt until the inrush limiter resistor and AC_BAT_SYS. (i attached my measuring in the picture below with red color font)

i get 3 volt on my +3v rail and ME_AC_PRESENT, but i didnt get correct number on +5, 1.5, 1.05, 1.2v and i got nothing on VCCIN

when i plugged the adaptor in (without battery) i felt hot on the surface on my processor and around bios ic down to lcd socket.

can anybody enlighten me what should i do/test in this case. pleasee

nb: i tried to replace the buck controller (NCP81108A ic) but no luck, i didnt realize that this ic need vccin as its power until i figure that i also missed my vccin.

[dellxps15]

Re: Need Help with Asus UX305F Mobo, power light on, charger light off, dead laptop

i higly suspect another nb chip dead..... remove jumper on 3.3 rail and see if volts and psu stay on

[wilson1002003]

Re: Need Help with Asus UX305F Mobo, power light on, charger light off, dead laptop

i higly suspect another nb chip dead..... remove jumper on 3.3 rail and see if volts and psu stay on

which one is jumper on 3.3 rail? do you mean this inductor?

and, why you suspect that the northbridge chip is the culprit? is this the reason why almost all component in VCCIN rail get shorted to ground?

[dellxps15]

Re: Need Help with Asus UX305F Mobo, power light on, charger light off, dead laptop

i had a similar problem.... 0 volt on pwbtn 0 volt anyehere.... and result was pch shorted.
jumper could be in the opposite side of board.

follow track of 3vadswo coil and see if near it is a jumper .. that side or opposite side
its just to make sure pch is ok or not...

you can also measure in diode mode pin 8 of bios and see if its shorted or not.

edit: measure also all that voltage rail on the picture u have and see if any of them is shorted

[wilson1002003]

Re: Need Help with Asus UX305F Mobo, power light on, charger light off, dead laptop

i had a similar problem.... 0 volt on pwbtn 0 volt anyehere.... and result was pch shorted.
jumper could be in the opposite side of board.

follow track of 3vadswo coil and see if near it is a jumper .. that side or opposite side
its just to make sure pch is ok or not...

you can also measure in diode mode pin 8 of bios and see if its shorted or not.

edit: measure also all that voltage rail on the picture u have and see if any of them is shorted

after rereading the power sequence, i think maybe maybe pch also my problem since its also responsible for sending signal to buck controller to work, also i feel that processor chip getting hot when i plugged the charger.

but, can you please please point out which one is the jumper from the image.. please.. my level in repairing mobo is still at the age of newborn baby..

is it the image i attached?

and what did you do with the jumper? did you plug out the jumper? or did you just short it? but jumper meant to be shorted right?

[wilson1002003]

Re: Need Help with Asus UX305F Mobo, power light on, charger light off, dead laptop

you can also measure in diode mode pin 8 of bios and see if its shorted or not.

i cant find datasheet of IT8585VG so i dont know which one is pin 8, but this is what i get with the component nearby. most of the component not shorted to ground, just one small resistor at the left hand of the ITE IC both leg shorted.

also i trace the 3vadsd rail and they are not shorted to ground.

i've measure the volt at most the point in the picture, 5v, 1.55v, 1.05, 1.2v all not present.

[dellxps15]

Re: Need Help with Asus UX305F Mobo, power light on, charger light off, dead laptop

pin 8 referred to bios chip.

a real good picture could help to identify 3.3 rail jumper. with all that line, color and not good quality picture is hard to read pjp and see if they could be the one we need.

[wilson1002003]

Re: Need Help with Asus UX305F Mobo, power light on, charger light off, dead laptop

pin 8 referred to bios chip.

a real good picture could help to identify 3.3 rail jumper. with all that line, color and not good quality picture is hard to read pjp and see if they could be the one we need.

will these pictures work?

and what did you do with the jumper on your case?