I have no idea what you mean by the half way mark (do you mean the point at which the silver 'button' is above the chute?). Are you running the grinder while moving towards the fine setting? If not, best to do so. Does the noise that you refer to sound like 'burr on burr' contact? You may have actually reached the zero point on the grinder. Empty the grinder, back the grind setting off a little from the point of 'resistance' or whatever it is that you are observing, check that there are no stuck beans, and then try grinding some beans.