As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SUSPECT FUME FROM AIR PACK ONE -PERFORMED TSM 05-50-00-810-831-A AND FOUND APU TO BE THE SOURCE OF THE ODOR EVENT. PERFORMED ENGINE RUNS WITH CREW USING HUFFER CART. PACK 1 AND PACK 2 CHECKS SATISFACTORY ON BOTH ENGINES; NO ODORS NOTED. A/C OK FOR SERVICE. MOC #120882. REF LOGPAGE 3427040-2 FOR APU DEFERRAL.