My X-Men does this, after extensive research (sticking my head inside) I found that the shaker cover is warped. It's typical of this kind of molded plastic. I haven't gone back yet to fix it. I know that if I take the cover off, move wires out of the way that the vibration noise is completely gone. The shaker was actually hitting the cover. You may want to check that and let me know if you fix it?