As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT ATTENDANTS REPORTED SMELLING BURNING RUBBER IN THE AREA OF ROW 27 WHILE AT CRUISE ALTITUDE. NO SMOKE WAS VISIBLE. LEFT AND RIGHT RECIRC FANS WERE TURNED OFF AND THE SMELL DISAPPEARED. INSPECTED FLOOR DUCTING AND CEILING IN AREA OF ROW 27. INSPECTED RECIR FANS AND FILTERS IN CARGO COMP. RECIR FANS AND AIRFLOW NORMAL. NO ODORS PRESENT.