As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: LAVATORY D SMOKE DETECTOR AURAL ALERT IN CABIN ENROUTE. CLEARED ITSELF SHORTLY. NO SMOKE SMELL. NO INDICATION IN FLIGHT DECK WHEN TRIGGERED. MAINTENANCE FOUND THE #1 CABIN INTERCOMMUNICATION DATA SYSTEM (CIDS) DIRECTOR NOT RESPONDING TO THE CENTRALIZED FAULT DISPLAY SYSTEM (CFDS) AND REPLACED IT PER AMM 23-73-34. A SATISFACTORY OPERATIONAL CHECK WAS ACCOMPLISHED WITH NO MORE CHIMING COMMING FROM THE AFT LAVATORIES.