While I am not even sure whose lasers B-D is using in FACScans these days,
many "adjustment-free" low-power air-cooled argon lasers of the type used in
clinical instruments such as the FACScan do have some provision for mirror
adjustment, and I have had to do this on occasion when a laser came from the
factory. "Walking" the mirrors reduced the current draw.
Is this an option?
-Howard