So tried various color and half tone calibrations. On other files such as Word Doc or printing from pages on internet - appear OK.
SO customer gave us a PDF file from publisher where it prints totally ok on small HP laser and a $400 Oki but on MX 4501 all colors and black are like 2 or 3 stops too dark. and can't get lighter. So went to 2 other Sharps - a 3500 and a 3501 all exhibited the same. Not certain what is going on.

Any clues/ ideas on this???

Thanks in advance