As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DIRTY SOCK ODOR THROUGHOUT CABIN ON GROUND WITH APU RUNNING. THE AIRCRAFT WAS GROUNDED. SMOKE ODOR AND FUMES TROUBLESHOOTING AND APU SMOKE ODOR AND FUMES TROUBLESHOOTING. NO ODORS IN CABIN OR FLIGHT DECK AFTER ENGINE RUNS AND TROUBLESHOOTING.