As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SMOKE DETECTOR ALARM SOUNDED IN AFT LAVATORY AFTER TAKEOFF AND A STRONG ODOR PRESENT UNTIL LEFT PACK TURNED OFF. FOUND LAVATORY SMOKE DETECTOR DEFECTIVE. REPLACED AFT LAVATORY SMOKE DETECTOR AND ACCOMPLISHED PACK BURN. SYSTEM GROUND CHECKED NORMAL OPERATION.