Stock Revo's EVX-2 on fire

[BrianG]

Which wire burnt? The red or black wire?

I can see something like this happening if the external LVC was hooked to the wrong set of ESC power leads. Generally, the overall ESC battery and throttle cable grounds are common. If you hook the external LVC to the wrong negative battery lead, you are placing the LVC ground at a half the full battery voltage potential and risk burning it out. TBH, if this is the case, I'm surprised it didn't blow sooner unless there is enough resistance in the circuit and wire to limit the current somewhat.