As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE, MAIN CARGO SMOKE WARNING ILLUMINATED IN FLIGHT. VISUAL INSPECTION REVEALED NO SMOKE IN CARGO AREA. FLIGHT CONTINUED TO DESTINATION, WHERE A LANDING WAS MADE WITHOUT INCIDENT. CLEANED SMOKE DETECTORS FROM NR1 TO NR 6. ON NR 1 REPLACED BOTH LIGHT BULBS, PERFORMED TEST OK. AIRCRAFT WAS RETURNED TO SERVICE. (K)