What was found
MCO FLT 1980 DURING CLIMBOUT FROM PBI, EN ROUTE TO PHL, CAPTAIN REPORTED VIA ACAR'S, STABILIZER TRIM PROBLEM. TRIM WOULD NOT TRIM FORWARD WITH SWITCHES. HAND TRIM IS POSSIBLE BUT FEELS LIKE IT BINDS. AUTOPILOT TRIM WORKS FINE. FLIGHT DIVERTED TO MCO AND LANDED WITHOUT FURTHER INCIDENT. MAINTENANCE FOUND THE PRIMARY STABILIZER TRIM ACTUATOR BAD. REMOVED AND REPLACED ACTUATOR AND PERFORMED SATISFACTORY TESTS OF PRIMARY AND AUTOPILOT STABILIZER TRIM SYSTEMS PER MM 27-42-71 AND MM 22-11-81.