If you have a known good working hopper and the motor is not running then its a power problem.
The hopper plug may have a loose wire but I would check your fuses as a more likely cause.
Turning the machine off/on isn't going to clear the machine from trying to make a pay.
They are highly resilient as to their last state. Ie if it was paying out, power at the casino died, when the power came on it would continue to pay out.
If it was in the middle of a reel spin, it would complete the spin when power came back. Etc Etc.
You can however press the white setup button multiple times until it appears to come back to the normal state then close the door and it will clear the 3300.
You would be good until the next time you hit any kind of pay out.