As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STRONG ODOR IN THE CABIN & FLIGHT DECK ON ARRIVAL. ODOR OF MUSTY SOCKS. THE AIRCRAFT WAS GROUNDED. COMPLIED WITH JC 26L00021001 AND FOUND APU AS SOURCE OF ODOR. RAN PACKS WITH ENGINE SOURCE WITH NO ODOR DETECTED. REPLACED THE APU IAW CARD 26L31049003. ALL OPS CHECKED GOOD.