Problem with shorted GPU? or just haunted board?

[BremiX]

Hello,

so where to begin...

EA/VA70HW REV 2.0

Laptop no power, only smoke coming out from area around adapter connector.

One of two power mosfets where making smoke so I removed it.

I will add a photo for reference (not my board in photo)

Connected power supply to adaper connector and board was taking 0.200ish A and fuse "220" did heat up. I replaced it with different "220" but it caught on fire... so I used "2R2" fuse, don't know what's the difference but no fire and no more 0.200 A. Instead it goes from 0.000 A to 0.080 in 6 seconds and stays like that. (did this without having 2nd power mosfet)

But now when I connect power supply to 2nd mosfet pins I get short and GPU is heating up...

Why?

Thank you for your time,

Raitis

[ktmmotocross]

Re: Problem with shorted GPU? or just haunted board?

uu can have shorted high side mosfet of gpu power rail, or reflowed/burned gpu

[BremiX]

Re: Problem with shorted GPU? or just haunted board?

uu can have shorted high side mosfet of gpu power rail, or reflowed/burned gpu

There was a bad AON6428 mosfet, no more short but another problem showed up. Looks like you can't swap 200 fuse with 2R2

Attached picture, want to know model of that IC.



edit: I think I found this IC. U8800A BQ24735RGRR 06V370000005

Battery charging IC.

[caspian]

Re: Problem with shorted GPU? or just haunted board?

you need a more powerful microscope to read the model of that IC.

[BremiX]

Re: Problem with shorted GPU? or just haunted board?

you need a more powerful microscope to read the model of that IC.

Eagle eyes!!

[BremiX]

Re: Problem with shorted GPU? or just haunted board?

I can power it on without this battery IC but there is no picture on a screeen only little light flicker...

[piernov]

Re: Problem with shorted GPU? or just haunted board?

If this was an high-side MOSFET shorted on the GPU power rail, chances are that the GPU is dead… Check first what voltage you get on this line.

About the charger IC, first check if both DCin MOSFETs are ok, then check if the resistance to ground of the +AC_BAT_SYS line is high enough.
Check also the current sense resistor R8808 marked R010.
If everything is ok then the charger IC could be dead, but first measure pins 1 to 11 and 20 to be sure of that.

[BremiX]

Re: Problem with shorted GPU? or just haunted board?

If this was an high-side MOSFET shorted on the GPU power rail, chances are that the GPU is dead… Check first what voltage you get on this line.

About the charger IC, first check if both DCin MOSFETs are ok, then check if the resistance to ground of the +AC_BAT_SYS line is high enough.
Check also the current sense resistor R8808 marked R010.
If everything is ok then the charger IC could be dead, but first measure pins 1 to 11 and 20 to be sure of that.

That charger IC is damaged caught on fire
Removed it.

Attached photo with mosfet I replaced 1 2 3 pins are 0.88 V but 4th is 1.10V, 5-8 are 19ish V, "330" cap under GPU gets 0.88V another near GPU gets 1.50V.

So we have fallen Nvidia gpu...?

Can I disable that GPU and use Intel HD Graphics?

[caspian]

Re: Problem with shorted GPU? or just haunted board?

If you find and upload the mainboard's schematics, you get better help to see if the conversion is possible.

[BremiX]

Re: Problem with shorted GPU? or just haunted board?

If you find and upload the mainboard's schematics, you get better help to see if the conversion is possible.

https://www.badcaps.net/forum/showth...ghlight=VA70HW

Here it is.

[caspian]

Re: Problem with shorted GPU? or just haunted board?

probably it is possible to convert, but I do not know how. you have to search the Internet to find if someone did it before.