I would suggest you check the circuit board
yourself. it may just be a simple component that
needs replacing.
I only say this as I did let the smoke escape
also, which resulted in an education on the
workings, that, in reality I would have preferred to
stay ignorant about, but none the less am glad I
undertook.
My experience was a valuable lesson in never to
return to the hangar after consuming alcohol. In the
dim light I hooked the battery up backwards,
resulting in the inevitable result and an adventure
in finding the source of the smoke and checking
every other component for damage. Luckily my EC2 was
ok but the electric CS prop controller was not built
as rigorous.
Andrew