Asus x55vd Rev 3.1 wont power up

[nels]

Hi All im trying to repair a Asus x55vd,

first power on led but no display no access to drive etc...
on boot, fan speed its high and after few moment its turn off itself.
and can't power up again until waiting many time not connected to charger and battery removed
otherwise led power up for 1 sec and shut off immediately.

i have flashed bios with arduino+serprog.
it boot and display working windows start but the problem speed fan high
an power off itself still.

think its a capacitor problem i read where https://www.elvikom.pl/asus-r503v-mb...7m-t50576.html
same motherboard whit same power problem the guy solved it replacing capacitors around rt8207m the mine is a rt8206L.

i have the great idea remove power source and short ceramic capacitor around rt chip to see if i can boot without waiting an identify the bad capacitor.
now it no power up anymore nothing happens wen i press power button .
i have only 2 pins with voltage :19v on Vin pin 6 of rt8206l and 6v on pin 4 LDO control.

any idea.
Thanks

[caspian]

Re: Asus x55vd Rev 3.1 wont power up

are you sure you had removed all the batteries and power sources? now, check resistance to gnd on that capacitor and report the resistance value. In addition, find where that capacitor is connected to.

[nels]

Re: Asus x55vd Rev 3.1 wont power up

hi Caspian thanks for reply

not all i don't have removed cmos battery,

i have 5 oms on this capacitor (1uf_16v) connected to pin 19 (Vpp) of the rt8206L.

[caspian]

Re: Asus x55vd Rev 3.1 wont power up

this means it is shorted. now you have to find which component is shorted. I hope it is the capacitor and not the rt8206L. first check if the capacitor is connected to any other point on the board other than rt8206L. then remove the capacitor and check if the short is gone or not.

[nels]

Re: Asus x55vd Rev 3.1 wont power up

its just connected in parallel to a resistor connected to pin 7 of rt8206L
i go to try unsolder capacitor an test it ,i hope its the capacitor too .

in motherboard the rt8206l its the primary source of the 3v,5v ?

thanks

[caspian]

Re: Asus x55vd Rev 3.1 wont power up

I do not know. just remove the cap. If the short remains, remove the resistor too.

[nels]

Re: Asus x55vd Rev 3.1 wont power up

not the cap ,the resistor is too small to my soldering iron i get new tools Thursday

[caspian]

Re: Asus x55vd Rev 3.1 wont power up

it would be very useful if you find schematics or boardview of this laptop. that capacitor is probably connected to another part of the mainboard which is away from rt8206L. In addition, a high quality photo of rt8206L and its surrounding components would help. I think it is not required to remove that resistor. measure the resistance that exists between the two sides of the resistor.