What was found
N42HN TOOK OFF FROM KCLT THE CAPTAIN NOTICED THE CABIN DID NOT SEEM TO BE PRESSURIZING. HE CHECKED THE SETTINGS & ASKED CONTROL TO COME BACK TO KCLT. ON THE WAY BACK THEY REALIZED THAT IT WAS WORKING & THEY LANDED AT KCLT. PERFORMED THE GND TEST & CHECKS ON THE SYS, CONFIRMED IT WAS WORKING & THEY CONTINUED ON TO KLZU WITHOUT PROBLEMS. CHECKED THE ACFT OUT & COULD NOT DUPLICATE THE PROBLEM. WHILE CHECKING OUT THE PRESSURIZATION SYS IT WAS NOTED THAT THE MINI CONTROLLER WAS SLOW TO RESPOND, SO IT WAS REPLACED WITH A REPAIRED UNIT & OPERATIONS CHECKED GOOD.