As long as it opens wide enough for the blade to be put into it and it closes tightly enough to shave with, I don't think there's any particular reason to "fix" a lazy silo door.
A lazy door would either be caused by a bent safety bar or a bent in end cap. Both can be easily fixed by slowly opening and closing the doors and determining exactly where it is catching, or rubbing, and then carefully bending it back into proper alignment.