I was trying to calibrate the top mounted rangefinder on my crown graphic and I messed up somewhere. I tried to follow these directions: https://lommen9.home.xs4all.nl/cams/index.html
and but now the second image doesn't move correctly (it hardly moves at all). All that I think I did was loosen the nut and then maybe bump the mirror accidentally. I tried to reposition the mirror and tighten the nut back up but now the second image doesn't move. I should have left well enough alone, but does anyone have any idea what I messed up?