As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: MOMENTARY SMOKE ALARM MID CABIN LAV DURING CRUISE. FLIGHT ATTENDANTS INVESTIGATED AND FOUND NO SIGNS OF SMOKE. MAINTENANCE REPLACED MID LAVATORY SMOKE DETECTOR FILTER AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK OF THE SMOKE DETECTION SYSTEM PER AMM 26-12-00 WITH NO ISSUES NOTED.