Ink rollers cannot accept or transfer ink.

pH/Conductivity of fountain solution to acidic Check and reset if necessary to manufacturers specs.
Ink rollers cannot except or transfer ink. Too much water being run. Reduce dampener settings. Check fountain solution for proper mix ratio.
Vibrator rollers Clean and desensitize. Rinse thoroughly. Re-ink.
Glazed Distributor and Form Rollers Remove and deglaze effected rollers. Replace and reset ink strips.
Over emulsification with ink Consult Ink and F/S manufacturers