Why do my servos buzz loudly even when stationary?

Question: Why do my servos buzz loudly even when not moving?

Answer: A loud buzzing noise from servos while stationary usually means they are under constant load or receiving jittery signals. First, check your servo's control signal with an oscilloscope or a reliable servo tester; noisy or unstable PWM signals cause the motor to constantly adjust, creating buzzing. Second, ensure the servo isn't mechanically binding or overloaded—free up any tight linkages and confirm the servo can move smoothly without obstruction. Third, verify your power supply delivers stable voltage and current; voltage dips can cause the servo to struggle and buzz. Finally, adjust your control code or transmitter trims to centre the servo properly; if the servo is being told to hold a position beyond its physical limit, it will buzz trying to maintain it. By checking signal quality, mechanical freedom, power stability, and correct positioning, you can eliminate most buzzing issues.