As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER INITIAL TAKEOFF ON FLAP RETRACTION GOING FROM FLAPS 2 TO FLAPS 0. NR 4 LED SLAT WOULD NOT RETRACT. RETURNED TO PHL, HAD TO GO TO FLAPS 5 TO GET GREEN LIGHT AND NORMAL POSITION. FOUND MOISTURE IN NR 4 LEADING EDGE SLAT ACTUATOR CONNECTOR. CLEANED SAME. OPS CK'S OK. NUMEROUS CYCLES PER M/M 27-82-011-4. AIRCRAFT OK FOR FURTHER SERVICE.