Hi, i bought the HGDRONEK66 and all connection and assembly i followed through the gitbook, but out of the four motors, one doesnt rotate. i tried switching the esc with different motors, others work fine with it. so the motor is the problem. is there anyway to check if the motor is operable or it is just faulty as i received it? the motor just jitters when i tried calibrating it and doesnt spins. havent tried flying yet.