As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: DURING DESCENT FLIGHT ATTENDANTS REPORTED DIRTY SOCK SMELL. MAINTENANCE ISOLATED THE SOURCE OF THE ODOR TO THE APU. MAINTENANCE ACCOMPLISHED SMOKE / ODOR / FUME TROUBLE SHOOTING TASK CARDS 26L00021001, 26L00021002 AND FOUND FLUID ON TOP OF THE APU AIR INTAKE INLET FLAP. MAINTENANCE CLEANED THE APU AIR INTAKE PER TASK CARD 26T31049006 AND AMM 49-16-00. NO ADDITIONAL LEAKS OR ODORS WERE NOTED.