As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: LE FLAPS TRANSIT AMBER LIGHT ILLUMINATED IN CRUISE AT FLIGHT LEVEL 380 WITH THE NR 3 LEADING EDGE SLAT ILLUMINATED ON THE OVERHEAD LE DEVICES PANEL. FOLLOWED QRH PROCEDURE. ROLL WAS ENCOUNTERED WITH DEPLOYED SLAT. MAINTENANCE REPLACED THE S3 OUTBD PROXIMITY SWITCH SENSOR IAW AMM 27-11-00.