Why do my servos buzz loudly even when stationary?

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

Answer: A loud buzzing from servos at rest usually means they are under constant load or receiving a jittery signal. First, check your servo’s neutral position in your transmitter or controller to ensure it matches the servo’s centre. If the signal is slightly off-centre, the servo will try to hold a position against its mechanical limits, causing buzzing.

Next, verify your control signal is clean and stable. Noise on the PWM signal can cause the servo to twitch and buzz. Use a high-quality servo tester or receiver and try swapping cables to rule out interference.

Also, inspect the servo horn and linkage for any binding or mechanical resistance; the servo motor struggles if it can’t move freely.

If the servo is powered at a voltage higher than its specification, it may buzz or overheat—ensure you use the recommended voltage (usually 4.8–6V). Lastly, try a different servo to determine if the issue is with the servo itself or the control setup.