What cause burned FET driver and FETS on 9920

[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...