Ink overflow.. On each end of the drum there is adjustments that can be made to the squeege. This is what scrapes the ink through the screen. These scrapers may be applying too much ink or internally too much ink is in the drum. These scrapers can be adjusted from each end. If you have a hard time getting the copy dark enough try to increase the flow of ink through.. this will take away the ink inside quicker. Another problem could be cheap aftermarket ink. I noticed i had a problem with one supplier that the ink was so thin it actually drips out of the drum when not in use.. The only other solution is to adjust the drum internally if the problem persists. This means removal of the drum to adjust ink flow.. This shouldn't be the problem..

Ink overflow. Fit new squeezy gear in drum.