As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 1791 CABIN DID NOT PRESSURIZE ON DEPARTURE NOTICED AT 9500 FT LEVELED 10,000 FT OUTFLOW VALVE WAS FULLY OPEN DID NOT DEPLOY VALVE DID NOT MOVE. PERFORMED IAW AMM TASK 21-31-710-801 OK FOR SERVICE. AS PRECAUTIONARY A TSI WAS ISSUE TO REPLACE THE OUTFLOW VALVE AND MODULE IN MCO.