As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE SUPERNUMERARY AREA SMOKE DETECTOR'S ALARM SOUNDED WITH NO SMOKE PRESENT AFTER OPENING THE COMPARTMENT’S DOOR. THE AIRPLANE WAS REMOVED FROM SERVICE (GROUNDED) AND THE SMOKE DETECTOR WAS CLEANED. THE CAUSE OF THE SMOKE DETECTOR'S ALARM WAS DUST IN THE SMOKE DETECTOR.