As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT CREW REPORTED THE LEFT AFT LAVATORY SMOKE DETECTOR WARNING ILLUMINATED IN THE COCKPIT WITH NO SMOKE OR FIRE INDICATION IN THE LAVATORY. THE WARNING EXTINGUISHED ON ITS OWN. ACCOMPLISHED A LEFT AFT LAVATORY SMOKE DETECTOR TESTED IAW AMM 26-14-00. TESTED GOOD.