As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: PILOT REPORTS SOF EVENT FROM DESCENT TO ARRIVAL AT THE GATE. THE FORWARD CABIN HAD A STRONG DIRTY SOCK LIKE ODOR. MAINTENANCE ACCOMPLISHED CARD 26L00001002 AND DETERMINED THE APU TO BE THE CAUSE OF THIS EVENT. MAINTENANCE REMOVED AND REPLACED THE APU OIL COOLING FAN IAW AMM 49-52-51. OPS AND LEAK CHECKS GOOD.