I went and got myself a decent soldering iron, removed the motor wires and then pulled the ESC apart over the weekend.

The solder where the red wire connects to the Rx was splashed all over another little component at the board, looked like it melted actually. And it was all brown/blown at the board.

I decided the ESC was toast, so am now looking for a replacement. Might just go a SpeedPassion combo or something and be done with it.

Thanks for the ideas/advice.