i had a servo whit a clicking sound in it.there where more byers who has this sound. so i thought it was normal,till today when i connected all in the robot. power up the robi and there was smoke,lucky i had connected the on/off swits. the damage hopefully is only wires. now i have to wait a hole week for a wire from less then 1 gram 7 cm long tired mad so never use a servo that makes any not normal sound.