first of all the mini reg needs to be 200psi. second when my mini would not fire with a rotor attached it was, because, the paintball were to small (.672).
drop test= fill the rotor up with paintball. then turn it on while holding a pod under the rotor. this test will make sure the rotor works. after you done it once. do it again and block the passage of the paintball and then move your finger. this will make sure to rotor feeds the paint then will continue to feed after its is been unblocked(this simulates you pulling the trigger stopping and pulling the trigger again). if the rotor works still after this test. than your rotor is fine. then you have to look into your mini.