As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT NR 286 - ATL-MCO - UPON LANDING GEAR EXTENSION ON APPROACH TO MCO THE LEFT MAIN GEAR DID NOT INDICATE DOWN AND LOCKED. FLIGHT CREW AND ATC CONFIRMED GEAR EXTENSION AND AIRCRAFT LANDED WITHOUT FURTHER PROBLEMS. MAINTENANCE FOUND LOOSE CANNON PLUG ON DOWNLOCK SWITCH. RESECURED AND CLEARED OPERATIONAL CHECKS OK.