As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING APPROACH OF FLIGHT 2734 LT MAIN GEAR DOWN LOCKED INDICATION DID NOT ILLUMINATE. LIGHT TESTED OK CYCLED LANDING GEAR AND THEN GOT 3 GREEN LIGHTS ON PREVIOUS APPROACH. LT MAIN LIGHT WAS VERY LATE ILLUMINATING. MAINTENANCE DURING TROUBLESHOOTING FOUND OIL IN CANNON PLUG CLEANED AS REQUIRED. CYCLED GEAR SEVERAL TIMES, ALL CHECKS GOOD AT THIS TIME.