What cause burned FET driver and FETS on 9920

[BrianG]

Andy is right, the cap would not have caused it. Using a cap with a higher voltage rating than needed is actually good since it won't be running close to the max rating. And those electrolytic caps usually come in v ratings of 6.3v, 10v, 16v, 25v, 35v and so on.

At most, a bad cap could maybe fry the BEC chip if it somehow internally shorted. But most BECs have a thermal and short-circuit cutoff.

After looking at the datasheets for the part numbers you posted, one is a FET driver IC, the other is indeed an output FET. Driver ICs don't usually go bad since they are low current devices. I would think that whatever caused that one to go bad, might have fried others as well.

Here are the datasheets if you're interested.

IR2102S datasheet
IRF7413 datasheet

[tom255]

I thougth same...
When i come home i will check cap on short circuit. hmm but on other side if in cap short circuit i supose that first thing what will burn its UBEC.
Anyway next week i will get parts so i try to resolder

[GriffinRU]

Driver can blow output FET's if it is overloaded and wasn't able top close FET fast enough, or didn't have built-in delay for protection... you can get the idea

CAP can course failing in driver if it doesn't have ESR low enough, Higher voltage caps have higher ESR then lower voltage ones.

It is always about balance, and drivers, FETS and CAP's are very sensitive to temperature you can finish the rest...

[BrianG]

Originally Posted by GriffinRU

CAP can course failing in driver if it doesn't have ESR low enough, Higher voltage caps have higher ESR then lower voltage ones

I was assuming the cap he was talking about was on a receiver plug, not part of the ESC. But maybe I read the post wrong...

[GriffinRU]

Originally Posted by BrianG

I was assuming the cap he was talking about was on a receiver plug, not part of the ESC. But maybe I read the post wrong...

My fault,

to tom255:
If you have bad cap in receiver it is very bad and there is no need to discuss what can happen to ESC, garbage in - garbage (smoke) out. Noise on input can kill any controller.

[zeropointbug]

Originally Posted by GriffinRU

Driver can blow output FET's if it is overloaded and wasn't able top close FET fast enough, or didn't have built-in delay for protection... you can get the idea

CAP can course failing in driver if it doesn't have ESR low enough, Higher voltage caps have higher ESR then lower voltage ones.

It is always about balance, and drivers, FETS and CAP's are very sensitive to temperature you can finish the rest...

Hence all these problems could be from the caps in these controllers... the more the merrier!