As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON ARRIVAL, FUMES, ODOR OF BURNED RUBBER FROM AFT CABIN AT 20000 FT. THEN AGAIN AT TOP OF DESCENT. PERFORMED CABIN ODOR FAULT CONFIRMATION TASK IAW TSM05-50-810-831-A. UNABLE TO CONFIRM FAULT FLIGHT CREW PACK ISOLATED LT AND RT ENGINE IDLE RUN AND AMM 71-00-00-710-006B & AMM 49-00-00-710-010. OK FOR SERVICE AT THIS TIME.