Hi all, I'm new to the Arducopter and am having an issue which I have been unable to resolve on my own that I am hoping this community can help with. I'm planning to use the APM2.5 to control a custom vehicle which uses Hitec HS-50 servos (relatively small ones, ~6g). All of my testing has been performed on a bench being powered through the APM power cable, and I've also tried powering my servos through an ESC with the JP1 jumper moved appropriately. In each case I believe I am getting a clean 5Vs. I am able to connect to the APM through the mission planner software and also have been successful modifying the code to send custom MAVLINK messages. I have not connected any RC equipment, only the servos, ESC, and telemetry radio.
The problem I am having occurs when I try to plug in my servos. I know they are not fried because I can control them using the DemoServo script provided, and I've tried different HS-50s as well. When I plug them in, they make a loud buzzing sound, like the servo is being driven at a very high frequency. Applying a little torque to the servo by hand indicates to me that it is being commanded, but again I believe the servo is being burned out by the way in which it is making noise, and know it is not normal behavior. I've tried writing custom commands in loop(), of the form APM_RC.OutputCh(CH_1,1500) to no avail, the buzzing continues.
Can anyone make a suggestion as to what I should check? Thank you for your help!