What was found
FLT 2973 - AFTER TAKEOFF FROM DTW, THE MAIN TRIM FAILED. RESET CIRCUIT BREAKERS, RESET STANDBY TRIM WITH MAIN TRIM, NO CHANGE. AIRCRAFT RETURNED TO DTW. AFTER LANDING MAIN TRIM WORKED NORMALLY. MAINTENANCE REMOVED AND REPLACED MAIN PITCH TRIM ACTUATOR WITH SERVICEABLE UNIT. OPS CHECK GOOD. (M)