How did your MMMv2 die?

[BrianG]

Definitely a BEC issue there. The Link supplies the 5v power for the brains, so it makes sense that it works then. But when you hook it up to batteries, the brains are no longer powered so it doesn't work.

Me thinks Castle should forego the switching BEC thing altogether. They can use a cheap linear regulator for the brains (not much loss because of the really low current), and package a CCBEC in the box for a few $$$ more. Worth it IMO.