As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: FLIGHT ATTENDANT REPORTED THAT AFT RIGHT LAVATORY SMOKE ALARM STARTED TO BEEP ONCE EVERY TWO SECONDS AND THE LIGHT CAME ON. NO INDICATIONS ON THE FLIGHT DECK. THE LAVATORY WAS EMPTY. AFTER ABOUT 5 MINUTES THE BEEPING STOPPED AND THE LIGHT WENT OUT. MAINTENANCE ACCOMPLISHED SMOKE DETECTOR CONTROL UNIT BITE TEST PER AMM 26-07-00 AND BITE TEST PASSED FOR ALL LAVATORIES,