Take the belt off the supercharger and turn the pulley back and forth. If there'* any play, the coupler is bad. If there'* play the tensioner will bounce a bit because the rotors are heavy. Check out this thread:
Change supercharger coupler
If your supercharger needs to be rebuilt, there are several members that have rebuilt ones they will sell you for a very reasonable cost.
Let us know what you find out.