As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CABIN PRESSURE CONTROL FAULT CAME ON AFTER TAKEOFF, CABIN WOULD NOT PRESSURIZE. PLACED CONTROL SWITCH TO MANUAL CABIN STILL WOULD NOT PRESSURIZE. RETURNED TO RDU. REMOVED AND REPLACED SECONDARY OUTFLOW VALVE IAW F-100 AMM 21-31-04. PERFORMED OPERATIONAL TEST OF SYSTEM IAW F-100 AMM 21-31-00, OPERATIONAL TEST GOOD.