ASUS u31sd LAPTOP WILL NOT TURN ON

[heavymachines]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

If you need help let me know..

you are more then welcome to assist sir...i am not the kind to wine about hijack post er whatever.....right now i am having him test cpu voltage regulation area to see what is going on in that area whether its over volting or under etc....

[opamp]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

See if you can find the kb controller. It's going to be an ic with over one hundred pins.

[opamp]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

If you find it take a picture of the ic and post the numbers on it.

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

The fets you have marked are now under the heat sink,since it was put back on.

[heavymachines]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

The fets you have marked are now under the heat sink,since it was put back on.

soldier test wires to it if you have to and pig tail it to where you can test it... be careful not to bridge connection or short wire together and may need to do that to each one ...safest way to check it

[heavymachines]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

looks like you will only need to do that on 2 of em the rest you should be able to test without pig tails....

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

you will need to walk me through this pig tail. do I do this on the back of the board? Also what size wire? can it be bare copper wire or does it need to be coated?

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

Can you show pin layout for testing the fets

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

See if you can find the kb controller. It's going to be an ic with over one hundred pins.

Where do I find this?

[heavymachines]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

Can you show pin layout for testing the fets

zoom in on the image i have it marked where to test ..you do the same for each fet that looks like that with the part numbers i listed....

[heavymachines]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

you will need to walk me through this pig tail. do I do this on the back of the board? Also what size wire? can it be bare copper wire or does it need to be coated?

no you will soldier directly to fet pin1 and another on tab..it can be a phone wire or similar and yes it needs to be coated , if you used bare wire you would be begging to fry things lol.... and pig tail it out from under heatsink so you can measure voltages...

[heavymachines]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

Where do I find this?

i looked in pictures cannot find it only one ic that may be it but the ic will be square and have visible pins on its edges.... unless it is bga which i doubt but never say never.....

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

I tested the first fet with 703oal. it had 19.48. so do all the fets pin number1 and tab. #1 pin is the only one tested correct.

[heavymachines]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

here is schematic for one of the fets.... give you a better idea where pin one is what you want to measure is source and drain voltages.....better yet use screw hole as ground and put positive on pin 1 measure then tab and measure sorry had a brain fart there....

[heavymachines]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

I tested the first fet with 703oal. it had 19.48. so do all the fets pin number1 and tab. #1 pin is the only one tested correct.

sorry remeasure as stated on post #114

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

I looked at the fet diagram you say to measure source and drain. According to the diagram thats pins 1,2 and 3 is that right

[heavymachines]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

we want to know what the input is and the output is to do this is negitive on ground which is screw holes on it copper face around the screw holes and positive on pin 1 and measure then move positive probe to tab which is output.... so those pig tails will still work i am tired and do this everyday all day long at work so forgive me for the slight brain fart....

[heavymachines]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

I looked at the fet diagram you say to measure source and drain. According to the diagram thats pins 1,2 and 3 is that right

pin 1 is fine for source and my bad pin 4 is just gate you want mb which is the tab that is drain....

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

we want to know what the input is and the output is to do this is negitive on ground which is screw holes on it copper face around the screw holes and positive on pin 1 and measure then move positive probe to tab which is output.... so those pig tails will still work i am tired and do this everyday all day long at work so forgive me for the slight brain fart....

I under stand, I appreciate the time you take to teach how to repair. I think I have it now

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

I tested the 6 fets I could see

1 tab
00.0 19.48
00.0 00.0
00.o 19.48
00.0 00.0
00.0 19.47
00.0 00.0