What was found
CLIMBING THROUGH 10,500 FT, RECEIVED A CABIN PRESSURE MASTER WARNING. RETURNED TO FIELD. LANDING UNEVENTFUL. INTERROGATED CDS, FOUND CPC FOR VALVE DATA FAIL AND CP CONTROLLER FAILED. REPLACED THE AFT OUTFLOW VALVE IAW AMM 21-31-16-000-8010, AND 21-31-16-400-801. FAULTS REMAINED IN CDS. UNABLE TO CLEAR FAULTS. PART DID NOT FIX DISCREPANCY. REPLACED CABIN PRESSURE CONTROLLER IAW AMM 21-31-06-000-801, AND 21-31-06-400-801. COMPLIED WITH A FUNCTIONAL TEST IAW AMM 21-31-00-720-801. FAULTS REMAINED CLEAR IN CDS AND DID NOT REOCCUR. COMPLIED WITH A PRESSURIZATION OF THE ACFT IAW AMM 21-00-00-863-801. TESTED GOOD. RETURNED TO SERVICE.