As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX - SMOKE IN CABIN VISIBLE FROM ROW 5 & 6. RINGING SOUND FROM LAVATORY SMOKE DETECTOR. NO VISIBLE FIRE. MAINTENANCE REPLACED THE NR 2 P2.5/P3 AIR PRESSURE SWITCHING VALVE. INSPECTED BOTH 6 & 7 BEARING SCAVENGE DRAIN LINES. NO DEFECTS NOTED. THE NR 1 & 2 ENGINE OIL LEVELS AT PROPER LEVEL. OPERATIONAL CHECK FLIGHT IS SATISFACTORY.