Servo humming

Radio is an airtronics RDS 8000. I'm not sure if battle switch is the correct term. The switch is on the left upper side under the "retract gear" this is how I bought it from another member on here. What you originally said makes sense. It only hums when the latch is locked. The end point probably needs to be adjusted. Can this be done directly on the servo or does it have to be done with programming on the tx?