What was found
ON TAKEOFF, THE LEADING EDGE SLAT DISAGREE MESSAGE AND LEADING EDGE LIGHTS ILLUMINATED. DURING FLAP RETRACTION, THE FLAP NEEDLES STOPPED AT FLAPS 1/2 POSITION AND DID NOT COME UP USING THE ALTERNATE PROCEDURES. AIRCRAFT RETURNED TO MIA AND LANDED WITHOUT INCIDENT. RESET THE POWER CONTROL AND SENSOR CIRCUIT BREAKERS ON NR 1, NR 2, AND NR 3 FLAP/SLAT ELECTRONIC UNITS. NO FAULTS WERE INDICATED, SYSTEM CHECKED NORMAL.