burn ccbec ?

[Jason]

last night I was tempted to use my airtronics 2.4ghz radio on my truggy and all is looked fine the mamba max red wire are disconnected.. I connected the mamba esc on throttle slot and the servo into the steering slot .. now the bec I was connected it to the battery slot on the receiver... all worked good for around 20sec then the bec have stopped working I touch it and it was HOT now the I think the bec was burn ... I used 12 cells in series to startup up the receiver and bec...

there is the the manual of my radio ...

www.airtronics.net/manual/MX-3FHSS.pdf

I have see the receiver a NONE BEC integrated maybe why the problem ?