As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 65, JFK-ABQ. RETURNED TO FIELD (JFK). FUMES IN CABIN AT C/P 20000 FEET BOTH PACKS ON; T/S FOUND FWD RECIRCULATION AVIONICS FAN 20 HQ NOISY GRINDING SOUND, POSSIBLE SOURCE OF FUMES ODOR. REMOVED/REPLACED AVIONICS FAN 20HQ, TESTED AEVC SYS/20HQ OPS OK. NO FUMES SMELL IN CABIN. A/C OK FOR COND SERVICE. RAN A/C ENGS AT IDLE AS PRECAUTIONARY MEASURE OPS OK AMM 71-00-00.