if:

1. The materials are poured into the machine more than needed

2. The screen is clogged.

If the material is oily or wet, the screen will get clogged up with dough and filters airflow. In that case you must pull out the screen, then wash and dry it.

If the breaker has tripped and you would like to reoperate the machine, empty the bowl, rotate the three spinner to check out if they get stuck. Clean the screen and then restart the machine.