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re-capping a motherboard
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lilshawn:
anybody know why a motherboard i re-capped 2 months ago would be bulging caps again? it had a couple up next the the CPU that where bulged so i replaced them and now they are popped again.  :angry:

power supply looks good.

BobA:
Might be a bad MOSFET overdriving the caps
daywane:

--- Quote from: BobA on March 22, 2010, 05:59:37 pm ---Might be a bad MOSFET overdriving the caps

--- End quote ---
???
more input please.
I had a motherboard with the same problem. I also had a damaged motherboard and noticed same caps.
I de-soldered them and replaced the bad with used good ones.
not been a problem for almost a year.

what is a MOSFET.? (never mind googled it)
http://en.wikipedia.org/wiki/MOSFET
so thats what those things are called.
BobA:
The MOSFETS are driven by a pulse width modulator and this controls the required voltages on the MB.   If a MOSFET shorts it puts too much voltage on the cap which can cause failure.   If the pwm malfunctions the cap may be over driven and be on longer than it's proper phase and this can also cause failue.

fatfingers:

Wait, wait...

So a MOSFET is really just a transistor?

I wish I understood electronics.

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