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Repairing a motherboard

Warg6

Apr 19, 2017
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Apr 19, 2017
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Hello everyone.
I have an old Gigabyte 8i915p motherboard with a burnt inductor (and a suspicious mosfet).
IMG_20170419_105437.jpg
According to schematics this coil is 0.6U/D/H/30A/3P so I tried typing this specs in a google search but came back with nothing.
coil.png
I found some type of inductors though with different but still close values like 1.85uH and 30A. And I have some type of inductors in hand which have codes on them like 60R, R50, R40, R25...
IMG_20170419_112245.jpg IMG_20170419_112303.jpg

So at this point I need some suggestion. Can I replace it with one of them that I already have in hand? If so which one to go for?
Or should I order a new one with the closest specs?
Thanks for any help.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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You would be best off rewinding that inductor with the same gauge of wire, assuming that the core is intact.
 

Warg6

Apr 19, 2017
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Apr 19, 2017
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Thanks for your reply Steve.

Rewinding it, like, by hand, with any copper wire with same gauge?
And do you have any opinion what could be caused that inductor to get burnt? A bad cap or something?
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Rewinding it, like, by hand, with any copper wire with same gauge?

Yep, there's only 4 turns, should be easy.

And do you have any opinion what could be caused that inductor to get burnt? A bad cap or something?

A short somewhere, it could be the mosfet, or the mosfet could have been a subsequent failure.
 

Warg6

Apr 19, 2017
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What do you think? Will it blow up?
IMG_20170419_174757.jpg

Now it's time for replacing the mosfet. I assume that has to be exactly same with the old one. Or am I wrong and any mosfet with close values would do the work?
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Keep your fingers crossed. :)

The mosfet should be the same or similar. Can you read the part number on it?
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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That's probably a 2SK3638.
 

Warg6

Apr 19, 2017
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Apr 19, 2017
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I replaced the mosfet with a similar one which I salvaged from an old motherboard.
Right after turning on the m/b, I noticed some smoke coming from the inductor.
So I think it's time to put it aside.
Thanks for your help anyways.
 
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