Hey,
try to resolve the problem by eliminating each of the possible components of the radio.
Start with trying out whether the servo or mechanism works at all on another system.
If it works its fine.
Then look if a random servo does respond to the gear or flaps channel on the radio.
If it works its fine.
Then try another receiver.
If it works its fine.
Try another radiosystem with the mechanism.
If it works its fine.
Well, I hope you got what I mean and can complete this chart yourself. Try not to be so hasty when you do the tests because that will make you do mistakes.