The pulp discharge has clogged up or pulp has gotten under the screen.
Disassemble the unit and rinse the drum. Ensure that the discharge chute is free of obstructions such as compacted pulp.
Cut pieces small and feed through slowly. If you need to use the pusher, then you are over feeding the unit. Allow gravity to feed produce through the unit.
The Juicepresso works by squeezing the fruit or vegetable through the screen. Juice will come out through the screen, and the waste or pulp is discharged from the bottom of the auger and screen. If the hopper is loaded too quickly before the previous piece has cleared the screen, or if the pulp has clogged up inside the juicer, the Juicepresso may force pulp through the screen or under it, causing more pulp to appear in your juice.