The buzzing is normal. There are tons of posts on this and I read them all in a search I did just a week ago. To check for binding, disconnect the control rod at the servo. Then push on the control rod by hand to move your aileron back and forth. If it moves free, don't worry about it. If it does bind (compare it to the other side) then put some CA remover on the area to try and free it up.

Joe