As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UNABLE TO PRESSURIZE ACFT AT 10,000 FT DIFFERENTIAL PRESSURE WAS .5 PSI. CHECKLISTS NO HELP. RETURNED TO FIELD. LANDING UNEVENTFUL. INTERROGATED CDS AND FOUND CP CONTROLLER FAIL AND CPC/OF VALVE DATA FAIL FAULT CODES. R & R THE CABIN PRESSURE CONTROLLER IAW AMM 21-31-06-400-801 AND 21-31-06-000-801. PRESSURIZED AND DEPRESSURIZED ACFT IAW AMM 21-00-00-863-801, 21-00-00-863-802 AN RIL 84-21-012. RE-CHECKED CDS FOR FAULTS, NONE FOUND. ALL CHECKS GOOD. RETURNED TO SERVICE.