As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PASSENGER WAS SMOKING IN AFT LEFT LAVATORY AND SMOKE DETECTOR DID NOT WORK. FOUND SMOKE DETECTOR FILTER VERY DIRTY, CLEANED AS REQUIRED. TESTED SMOKE DETECTOR SYSTEM IAW AMM 26-17-00-710-001A. ALL LAVATORIES TESTED OK. AIRCRAFT OK FOR SERVICE.