Clearing a Ball Jam
Remove a battery
Remove all balls from the bin
Pull back on the retractable plastic part at the bottom of the ball bin
While pulling back, reach into the ball bin opening, and remove the ball
These steps are shown in the video linked above
Avoiding Ball Jams
Do not use wet or damp balls
Do not use balls that are moderately or heavily worn
Do not overfill the ball bin
If playing platform tennis, only use Volley branded balls