[jhautz]

You might have just toasted the internal BEC. Did you pull the red center wire on the plug that goes from the esc to the RX. This disables the internal BEC. I'm not sure what the cell limit is on the internal BEC for Mtronics, but I know w/ the quark the limit is opnly like 8 cells. With a higher cell count you need to run a rx pack or get an external bec unit.

The rest of the battery wiring looks good. Make sure you dont have some wierd short from a stray sloder blob or something. Other than these 2 things I have no other ideas. Could just be a bumm ESC.