Help, my retracts not respond

I buy a Turnigy Full Metal Servoless Retracts with Oleo Legs (Tricycle, F86 type) http://www.hobbyking.com/hobbyking/store/31832Turnigy_Full_Metal_Servoless_Retracts_with_Oleo_Legs_Tricycle_F86_type_.html but when i connect in my rx dont respond, i change the rx, and nothing, change to other retract and is ok, what i do ???