As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
L4 LAVATORY SMOKE DETECTOR PRODUCED AN INTERMITTANT AURAL WARNING. NO SMOKE NOTED IN LAVATORY AREA. PERFORMED FIM 23-39-00-810-910, THEN REPLACED ZMU NR 3 IAW AMM 23-39-04. PERFORMED LAV SMOKE DETECTION OPS TEST, THEN NO SMOKE DETECTOR FAULT SHOW.