Um.. the situation was quite strange la: The orientation of the fan was not correct so that its magnetic field goes against the magnetic field of the Motor, and.. as you know, the fan got stuck and could not rotate la. But then my frd didn't realize wo.... so the fan kept taking current from the receiver.. and finally... receiver burns jor !
Yes ar. 焊 together with the red/black wires from the ESC, so that once u connect battery, the fan will start la (even the ESC is turned off). sorry ar... i can't type chinese....