Diagnosis
The reamer (the spinning cone) is not making proper contact. The fruit is riding on top of it.
How to Fix It
Check the installation. The reamer must be pushed down fully onto the motor drive shaft until it clicks. You will feel it engage. When using it, apply firm, steady downward pressure on the fruit feeder cap. Do not just let the fruit rest. The pressure forces the fruit into the reamer's teeth.
If That Didn't Work
The reamer's plastic teeth may be worn down or clogged. Unplug the unit. Remove the reamer and inspect. Clean any impacted pulp from between the teeth with a stiff brush. If the teeth are smooth, the reamer needs replacement.
Heads Up
This juicer is for soft fruits only (oranges, lemons, limes). Do not try to juice apples, carrots, or ginger. It will stall and wear the teeth instantly.