As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FOR FLIGHT 3892 THE CREW REPORTED THE LAV SMOKE DETECTION LIGHT WAS CONTINUALLY ON. THE AIRCRAFT WAS REMOVED FROM SERVICE. PERFORMED OPERATIONAL TEST PER MM 26-16-00. THE OPERATIONAL CHECK WAS NORMAL OK FOR SERVICE. THE AIRCRAFT WAS RETURNED TO SERVICE.