ASUS u31sd LAPTOP WILL NOT TURN ON

[CR Designs]

I Have a Asus model U31SD. A phone charger was plugged in to it my mistake. now it will not turn on. The power Led light comes on and the leds across the front of the laptop come on. But the hard drive led stays off. I get no display. Hope some one can help on this one. thanks

[nish_pinto]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

Damn, do you get a fishy smell?

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

can any one tell me where to start looking for the problem on this laptop?

[heavymachines]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

take motherboard out and take clear pictures of both sides of motherboard and provide the part number off the motherboard so we can find schematics and look for anything obvious... and what was the phone charger voltage rating? have a hard time believing 5 volts could damage a laptop that is meant to run anywhere from 16 to 20 volts...most likely yours run at 18 to 19 volts respectively....



have you tried resetting the laptop by pulling battery and holding power button for 20 seconds and re insert battery and power to see if it will power on properly? or resetting bios before you tear it apart?

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

Did the hold down power button,didn't work. I already started to tear down. Did not reset bios. I'm taking out the mother board. It's not going easy. As I could not fine anything on line to see how to tear down. Will post pictures when I get it out. Thanks

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

I don't know what the voltage was on the phone charger. My Daughter did at her work.

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

Here's the pictures you wanted of front and back of MB. Let me know if you need more. Thanks

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

Here's what I found for the parts number on the board.

Asus
u31sd
Main Board
Rev 2.0
Hannstar
MV-4
94V-0

[heavymachines]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

Here's the pictures you wanted of front and back of MB. Let me know if you need more. Thanks

will need pictures of both sides of motherboard where dc jack power goes into the board clear and focus. please remove heat sink and carefully salvage any thermal pad you find.
....

[heavymachines]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

and to make sure details are correct it will respond to power button and turn on and get power led , did the fan spin at start up? but no hdd led and display?

i am sure it won't work but as rule of elimination pull the button cell batter for 5 mins and put it back in and connect the power button and display on a non conductive surface and put ram in and see if you can get anything... you can do this without putting it all back together just make sure nothing can short...

of course do above before you remove heat sink and get close up pictures..


so far i am not finding any schematic on this board...maybe somebody will chime in with one hopefully...

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

That's right when you press power button the power LED light comes on and you get Led lights on the front,but no hard drive Led light. No fan spins or sounds. I will take for picture and test as you said. thanks

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

Did test as you stated. still get just the Led light when I push the power button.No fan spins,display or sounds. Will get more pictures of DC jack.

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

Here's pictures of DC jack

[heavymachines]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

Please remove heat sink and take another photo of the area of the pic i edited

i believe there are more important ic's i cannot see due to the heat sink..

i will need those part numbers and if there is another 8 pin mosfet hidden under the heat sink?


you will need to reapply thermal compound before you put heat sink back on...but first we need to find the problem


do you have a digital multimeter handy?

[heavymachines]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

edited pic's

[heavymachines]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

and on third picture please remove the tape and ribbon i cannot see the traces nor any ic if there is any.... and take another photo of the 3rd picture and straight above shots please those angle shots are worthless... and make sure the light does not blind out the board i need to be able to see thanks...

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

When you say remove heat sink you want me to remove the whole unit I have circled in picture that includes the fan and over the CPU.

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

Here's the pictures you wanted where the tape had to be removed. Also in the other picture is the parts numbers you wanted. I do have a multimeter

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

Here's pictures with the heat sink removed.

[CR Designs]

Re: ASUS u31sd LAPTOP WILL NOT TURN ON

Any help would be appreciated on this laptop. Thank you