asus x555ld no power

[mmdqn]

hello everyone i have a question. When i connect the adapter to the motherboard the voltage goes 1v-1.5v-0.5v and flickers like that. what could this be caused by. Im a beginner and searched a lot on the forum but didnt find anything to help me

[Techtiger]

Re: asus x555ld no power

Dissemble the laptop look for any Burn components most likely a shot you can find the Bordview for this MB

[mmdqn]

Re: asus x555ld no power

i found 2 burned transistors and replaced them but i still get a short....

[Vesko356]

Re: asus x555ld no power

i found 2 burned transistors and replaced them but i still get a short....

Try to inject 1v~2A to 19V power rail and find what is getting hot, most probably shorted cap somewhere.

[mmdqn]

Re: asus x555ld no power

I don't have a variable power supply any ideas how to do it without one ?

[Vesko356]

Re: asus x555ld no power

I don't have a variable power supply any ideas how to do it without one ?

18650 battery is commonly used for the purpose, but is kind of dangerous if you don't know what you are doing



>>>Link to Youtube video for you to see how it works<<<

[Techtiger]

Re: asus x555ld no power

i found 2 burned transistors and replaced them but i still get a short....

Upload the pic of the area you have replaced Transistor PQ? Did you check for the bordviewr

[mmdqn]

Re: asus x555ld no power

soo i found the area of the short. checked the components 1 by one and the ones in red are shorted to ground i checked the others connected to the PU8200 and they are fine. also i removed the pu8200 to check if the short would dissapear and it didnt. Any help would be appreciated.
EDIT: not sure why the image won't load so ill add an imgur link. https://imgur.com/a/tcGWh8x

[Vesko356]

Re: asus x555ld no power

soo i found the area of the short. checked the components 1 by one and the ones in red are shorted to ground i checked the others connected to the PU8200 and they are fine. also i removed the pu8200 to check if the short would dissapear and it didnt. Any help would be appreciated.
EDIT: not sure why the image won't load so ill add an imgur link. https://imgur.com/a/tcGWh8x

Because you must tag the image address not a web page, so to speak tagged address must be ending with *.png or *.jpg and so on.

https://imgur.com/a/tcGWh8x ---> Not OK
https://i.imgur.com/CqLzzqr.png ---> OK

Upload the boardview and schematic here, this image alone is not enough to see what we are talking about.
The image:

[mmdqn]

Re: asus x555ld no power

here is the boardview

[Vesko356]

Re: asus x555ld no power

here is the boardview

Excellent, now it's way bettеr.
I saw quickly the boardwiew, and will suggest to open the jumper PJP8200, then to check if the short is still present or not, if the shot is gone check the caps PC8205, PC8206 and PC8207 then come back with the result here.

[ktmmotocross]

Re: asus x555ld no power

before u inject voltage to main rail, u must check if u dont have shorted some of high side mosfet

[mcplslg123]

Re: asus x555ld no power

before u inject voltage to main rail, u must check if u dont have shorted some of high side mosfet

Rightly said. It's a must and those who ignores these basic steps, kills the cpu/gpu.

[mmdqn]

Re: asus x555ld no power

so i opened the jumper PJP8200 and checked the 3 caps PC8205 PC8206 PC8207 and they are not shorted but im still getting a 0.00 on both sides pc8217. i removed it and checked and it works

[mmdqn]

Re: asus x555ld no power

i didnt inject voltage into the 19v rail because i dont have a variable power supply or any good 18650 cells

[Vesko356]

Re: asus x555ld no power

before u inject voltage to main rail, u must check if u dont have shorted some of high side mosfet

Rightly said. It's a must and those who ignores these basic steps, kills the cpu/gpu.

Question - applying 1v to the 19v power rail will cause a problem with the cpu/gpu or not?

so i opened the jumper PJP8200 and checked the 3 caps PC8205 PC8206 PC8207 and they are not shorted but im still getting a 0.00 on both sides pc8217. i removed it and checked and it works

Check caps PC8226 PC8227 PC8203 PC8201

...also i removed the pu8200 to check...

BTW it is still removed from the board or you solder PU8200 back in place?

[mmdqn]

Re: asus x555ld no power

pc8226 is empty on my board because it is not the exact model as the schematic but it is shorted i get 0 on both sides.
PC8203 PC8201 are not shorted and yes i did put back pu8200 because the short didnt go away with it removed.

[mcplslg123]

Re: asus x555ld no power

@Vesko356, my comments not meant for you. Lots of newbies join our forum and they do commit this type of silly mistakes. As far as your question or comment about 1V-2A power on B+ rail is definitely not going to kill cpu even if high side fet is shorted.

[mcplslg123]

Re: asus x555ld no power

@mmdqn, it will be a puzzle to actually find a shorted cap without lab psu. Get one for you at the earliest.

[mmdqn]

Re: asus x555ld no power

is there a cheap one you can recommend ?