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Mosfet faulting

ordi

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#1
Hello
i have a toshiba A100
and nothing appears good on it.
No running, just blinking orange led.

So i disasemble that laptop, and i test board and found some fuse and mosfet.
Which one i have to change ?

How to test a 8 legs MOSFET on laptop board mobo ?


Thank :wtf:
 
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#2
find the schematics of the transistor, and then test each pin with a current to see if it passes the current through to it's matching pin. alternatively you could try it blindly, it would just take longer to find where each signal SHOULD go, then to figure out whether it's actually going there. it's usually the opposite pin, but you never know for sure and it can confuse things.

example:
http://www.youtube.com/watch?v=2BU7qHWtsmQ
 

ordi

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#3
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#6
well the safer way would be to desolder it . you don't want to pass voltage through a trace you don't know about.

regardless of how your laptop is behaving, the individual components can still be tested. there is no guarantee it's the mosfet or the same issue from the link you posted, but you have to start testing somewhere right?
 

ordi

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#7
thank you digibucc
but which one i have to desolder ....Q518 or Q519 ???
or i have to test another cap or component ?
Thanks
 

ordi

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#8
it's about no power, no lights...
Just when i plug the power supply on it, it's blinking orange led only...no contact.
So it's for me a power problem (around mosfet, or fuse). But i test with and without voltage, the fuse but nothing wrong !!! And now i test mosfet and also, nothing to tell you !! Just to tell you what i have to test please !
 
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#9
hmm.. i'm afraid this is going beyond my knowledge... i will see if i can find anything though
 
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#11
If you don't even know how to check a fuse, I'd say forget about fixing it. Give it to someone who knows what he's doing.
You're almost guaranteed to damage something and make the entire thing unfixable, even for a pro.

I've seen so many user-FUBAR'd electronics over the years it ain't funny anymore.
(cut traces, damaged vias, accidental shorts destroying tons of parts, ripped-off solder pads, ...)
 
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#14
i know this sounds silly but have you tried it without the battery usually a blinking orange light is faulty battery.
 

ordi

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#15
Yes i test this battery ? I found maybe IC bq24721 is faulting.
What do you think about it ?