As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED. AT CRUISE, FORWARD LAVATORY SMOKE LIGHT ILLUMINATED AND ORAL ALARM ACTUATED FOR APPROXIMATELY 5 SECONDS, THEN CEASED. NO SIGNS OF SMOKE OR FIRE IN THE LAVATORY. PERFORMED LAVATORY SMOKE DETECTION SELF TEST, REF AMM 26-14-00, NO DEFECTS NOTED AT THIS TIME. OPERATIONAL CHECK NORMAL.