Hi Larry,
Welcome to the forum.
So have you ever heard of a scanner going bad
No I've not heard of such a thing but older scanners have some sort of fluorescent light source I think so I can imagine those could degrade over time.
LED scanners (Canon Lide) are particularly recommended for use with PP.
It may help to go back the scanner driver - can it make "raw" images from scans, ie. no adjustment made by the scanner software? I use Vuescan software which does have that feature.
Terry