Mamba Max Magic smoke!

[BrianG]

Castle's out of warranty service for any failure for the MM is $50: http://www.castlecreations.com/support.html

Obviously, that would be cheaper than a new ESC.

Since it was running for a long time, I would suspect "tired" caps. And then they go, FETs will follow shortly after. Running a MM on something heavier like a Revo will tend to push that small ESC more so than if you were running something bigger like a MMM. Sure, it works, but it does get stressed more.