As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF, FLAPS RETRACTED, THE LEADING EDGE FLAPS TRANSIT AMBER LIGHT REMAINED ILLUMINATED. FOLLOWED QRH PROCEDURE AND LIGHT STAYED ON WITH THE NR 4 LEADING EDGE FLAPS SHOWING AMBER. AN EMERGENCY WAS DECLARED AND THE FLIGHT RETURNED TO DEPARTURE WITHOUT FURTHER INCIDENT. THE AIRCRAFT WAS GROUNDED. TROUBLESHOOTING THE LEADING EDGE FLAP LIGHT IAW FIM 27-88-00, VERIFIED HARD FAULT. REPLACED PROXIMITY SENSOR S175 IAW MM 27-88-11, ALL SYSTEM OPS CHECKED NORMAL.