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 usually means they're constantly trying to hold a position under load or receiving a noisy signal. First, check if the servo is being commanded to hold a position under strain—if it’s pushing against a mechanical stop or heavy load, the motor works hard and buzzes. Try disconnecting the servo horn and powering the servo to see if the noise persists without load. Next, verify your signal quality: use a clean, stable PWM signal from your controller or receiver. Electrical noise or incorrect pulse widths can cause the servo to jitter and buzz. Also, ensure your power supply provides steady voltage (usually 4.8–6V) and enough current; voltage drops can cause erratic servo behaviour. Lastly, inspect the servo for damage or wear—internal gears or motor issues can cause buzzing even when stationary. If the servo buzzes without load and with a clean signal, consider replacing it. Taking these steps will help you identify and fix the cause of servo buzzing.