The lock on my MB8200 bottom box it's stuck. I know the key is correct. In fact it locked the box a few days ago. Now the lock won't turn. Not even a lite. It's as if I have the wrong key but the key matches the number on the cylinder. I looked in the gaps between the drawers with a flashlight and it does not look like anything it's jamming it. Any ideas? At this point, I doubt things like drilling the lock would help as I think the mechanism must be jammed.