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