As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SEA- F/A REPORTS STRONG "BURNING PAPER" ODOR MID CABIN TO AFT CABIN. SMOKE ODOR DID NOT DISSIPATE AFTER BLEEDS WERE TURNED OFF. PERFORMED OPERATIONAL TEST OF THE BLEED AIR SYSTEM REF AMM TASK NR 36-11-00-710-802. OPS TEST GOOD, NO INDICATION OF SMOKE OR ODOR WITH A/C AT RATED POWER NO INDICATION OF SMOKE OR ODOR. NO FURTHER DEFECTS, AIRCRAFT RETURNED TO SERVICE. NO PARTS REPLACED.