As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
REPORT OF DIRTY SOCK SMELL IN CABIN. GROUNDED - YES. ACCOMPLISHED CABIN ODOR TROUBLESHOOTING & FOUND OIL CONTAMINATION IN APU LOAD COMPRESSOR CASE REF FIM 05-51 TASK 814. REMOVED AND REPLACED APU REF AMM 49-11-00/401. ACCOMPLISHED APU INSTALLATION TEST REF AMM 49-11-00-400-803 NO SMELLS NOTED.