As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ACFT HAD A DIRTY SOCK ODOR WITH THE APU AND PACKS RUNNING. THE AIRCRAFT WAS GROUNDED. MAINTENANCE ACCOMPLISHED ODOR TROUBLESHOOTING CARDS 26L00021002, 26L00021001, AND DECON CARD 26L00021004. REPLACED APU MAIN INLET AND OUTLET PRESSURE FITTING O-RINGS IAW MM 49-21-00 AND TURBINE BEARING O-RINGS IAW 49-91-53, WASHED APU IAW MM 49-20-00-100-001-A. NO ODOR NOTED.