What was found
(CAN) DURING CLIMB PHASE, SLATS RETRACTED, NR 1 SLAT, HOWEVER DID NOT SHOW RETRACTED. FLIGHT CREW CONFIRMED THAT AIRCRAFT DID NOT HAVE ANY UNCOMMANDED ROLL IN THE FLIGHT CHARACTERISTICS. THIS INDICATED AN INDICATION FAULT ONLY. CREW RETURNED TO POINT OF DEPARTURE AFTER DUMPING 7300 LBS OF FUEL WITHOUT FURTHER INCIDENT. MAINTENANCE CONFIRMED SLATS FUNCTIONAL AND ONLY INDICATION AT FAULT. ACTUATOR WAS REPLACED AND AIRCRAFT RETURNED TO SERVICE.