What was found
(CAN) PILOT REPORTED A SNAG OF FLAPS NOT RETRACTING. THIS ACFT HAS THE MCOF52617-1 TRAINER MODIFICATION INSTALLED WHICH INCLUDES A FLAP PRESELECT SYS. THE SELECTOR WAS INSPECTED AND IT WAS NOTICED THAT THE CONNECTION BETWEEN THE FLAP HANDLE AND THE FLAP PRESELECT POTENTIOMETER WAS OUT OF PLACE. IT IS A ROLL PIN THAT HOLDS A SMALL GEAR ONTO THE SHAFT OF THE POTENTIOMETER. THE PIN WAS 75 PERCENT OUT OF THE GEAR. THE PIN WAS REINSTALLED AND SECURED WITH SAFETY WIRE TO PREVENT A FUTURE OCCURENCE. THE END RESULT WAS A FAILURE OF THE FLAP DYNAMIC BRAKE RELAY. THE RELAY WAS REPLACED AND FLAPS RIGGED WITH NO FURTHER ISSUES.