They should all be somewhere between the lowest setting and the highest setting, but not all the highest.
There should be 5 or 6 knobs on the neckboard depending on the monitor. There should be R Drive, R Cutoff, G Drive, G Cutoff, B Drive, and B Cutoff. Some don't include a Red Cutoff. None of them should be 100% of the way off, unless your chassis needs a cap kit or the tube needs a rejuvenation.