Why do my servos buzz loudly even when stationary?

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

Answer: Loud buzzing from servos at rest is usually caused by constant electrical current trying to hold the servo shaft in position. This happens if the servo is under mechanical load or if the control signal is jittery. To reduce buzzing, first check your servo horn and linkage to ensure nothing is binding or putting strain on the servo. Next, verify your control signal is stable—use a good quality servo tester or a microcontroller with clean PWM output. If the servo is still buzzing, try reducing the holding torque by gently moving the servo arm and allowing it to relax, or adjusting your controller’s neutral pulse width slightly. Also, ensure your power supply provides stable voltage and current; a weak or noisy supply can cause servo jitter. Finally, if the servo is old or damaged, internal gears or the motor may cause noise and might need replacement. Following these steps should help minimise buzzing and improve servo quietness when stationary.