Setting up a newly built kit and having a problem with the elevator servo. Using a servo tester/centering device I centered the Tower Pro servo and attached the arm. However, on installing the servo and plugging it into Power Up elevator slot the arm swings and locks in the extreme up position. There is no way adjust the arm into a position that will correct this. Anyone had a similar experience or some suggestion to correct it and center the servo arm. Thanks for any help.