As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT VENTILATION SYSTEM HAS THE DIRTY SOCK SMELL. OPERATED APU AND PACKS. VERIFIED DIRTY SOCK/OIL ODOR IN VENTILATION SYS. PERFORMED T/S PER FIM TASK 21 00 00 810 806 AND AMM 05 60 00 280 801C AND FOUND OIL LEAKING FROM APU LOAD COMPRESSOR CASE DRAIN. REPLACED APU PER T/C 78349010 AND MM 49 11 00. LK AND OP CHECK NORMAL. NO MORE DIRTY SOCK SMELL.