As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MUSTY ODOR FROM AIR CONDITIONING SYSTEM. PERFORMED TSM 21-00-00-810-801-A, FOUND OIL AT THE APU AIR PLENUM DUCT. FOUND NO OIL CONTAMINATION INTO THE PACKS. PERFORMED DECONTAMINATION OF ECS IAW AMM 21-00-00-615-001. NO FURTHER DEFECTS NOTED. REMOVED AND REPLACED THE APU.