Do you have another machine that you can put this stacker into? When the Stacker runs listen to the motor, it should be smooth, not noisy. If it’s making a lot of noise it not worth fixing. After it cycles try pushing up on the pusher plate that pushes the bills into the stacker, if you can push it up a little check the spring on the side of the Stacker, if it’s not broken the Stacker is probably worn out if you can push up on the pusher plate. We don’t fix them anymore because they are only about $225 -$230 new, by the time you get parts and labor into a used stacker your almost over half the cost of a new one.