As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX - AFTER TAKE-OFF, THE LAVATORY SMOKE DETECTOR WENT OFF. THE FLIGHT ATTENDANT VERIFIED THAT IT WAS ON, BUT NO FIRE OR SMOKE WAS NOTICED. THE DETECTOR SILENCED AFTER APPROXIMATELY 2 MINUTES. THE UNIT TESTED OK. MAINTENANCE INSPECTED THE DETECTOR AND IT TESTED GOOD IAW-8 (400) 26-12-11, TASK 26-12-11-710-801. THE AIRCRAFT WAS RETURNED TO SERVICE. NO PARTS WERE REPLACED.