What was found
(CAN) AFTER TAKEOFF DURING THE INITIAL CLIMB, THE CREW COULD NOT GET THE FLAPS TO RETRACT. THE CREW RETURNED TO ORIGIN & CONTACTED MX. THE FLAPS WERE RESET TO ZERO & THE ACFT WAS RELEASED UNDER THE MEL PROTOCOL & THE ACFT CONTINUED ITS RUN. ONCE THE ACFT WAS INSPECTED BY MX IT WAS DISCOVERED THAT WIRE C43A22 AT THE SPLIT FLAP SWITCH WAS CHAFED & THE TERMINALS ON THE SWITCH WERE CORRODED. WIRE WAS REPAIRED & THE SWITCH CLEANED & INSPECTED IAW WDM 27-51-01. A SUCCESSFUL FUNCTION CHECK WAS CARRIED OUT IAW OEM INSTRUCTIONS. THE SUBJECT MEL WAS CLEARED & THE ACFT RETURNED TO SERVICE.