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 are receiving a continuous signal telling them to hold position under load. This causes the motor to strain and vibrate. First, check your servo’s control signal: if it’s slightly off-centre or jittery, the servo will constantly try to correct its position, leading to buzzing. Use a stable and correct PWM signal (typically around 1.5 ms pulse width for centre). Next, examine the mechanical setup—if the servo is under heavy load or forced against a hard stop, it will buzz trying to maintain position. Try removing the load or repositioning the servo horn. Also, verify your power supply voltage is within the recommended range (usually 4.8–6.0 V); too low voltage can cause buzzing. Lastly, if the servo is old or damaged, internal gears or the motor may cause noise. Testing with a new servo can help identify this. Adjusting signal quality, reducing load, and ensuring proper voltage usually stops the buzzing.