Burned 2 mosfets on Quark33A

[TMASTER]

I just recently started running 4 cell lipo (14.8v) with a 450TH motor (29amps max),Futaba gyro, and 4 micro servos.

After about 5min the heli just dropped out of the sky. The BEC side of the board is fine. Two of the mosfets are burned next to the voltage input side. But they only burned pins 1,2 and 3.

So whats happening here? The Quark still works fine when I run it on the bench. And theres no way I was pulling over 20 amps. The quark is sopposed to handle 55 surge.

Anyways I found the chips on Digikey for $3.59 each.
Heres the data sheet: http://www.irf.com/product-info/datasheets/data/irf7831.pdf

Any info would be appreciated!

[write2dgray]

Hmmmm...very strange that it would smoke under that load. I would avoid the self-repair on that one and get it back to Quark for forensic analysis. That said, I don't know what their return and exchange policy is like.

[phil_g]

Is it possible that the motor threw a magnet & jammed, so it was stall current that blew the mosfets?
That would account for it 'dropping out if the sky' too - normally a blown mosfet wouldnt stop the motor as they usually blow open circuit leaving the others to do the work...
Phil