What was found
MASTER CAUTION ACCESS DOORS CARGO DOORS ENTRY DOORS L/R CABIN ALTITUDE WAS RISING FROM 8,500 FT TOWARDS 9,200 FT AT A RATE OF 500 FT / ??? WE EXECUTED AN IMMEDIATE DESCENT TO 14,000 FT AT WHICH POINT ALL EICAS MESSAGES CLEARED MAX CABIN DIFFERENCIAL REACHED 8.7 CABIN ALTITUDE MASTER WARNING LIGHT AND EICAS MESSAGE DID NOT ILLUMINATE CABIN OXYGEN MASKS DID NOT DEPLOY CABIN ALTITUDE STABILIZED BRIEFLY AT 14,000 THEN BEGAN TO CLIMB AGAIN TOWARDS 9,500 FT THUS WE INDICATED FURTHER DESCENT TO 9,000 FT WE COMPLETED THE CARGO DOORS QRH (PAGE 1.4) AS THE FWD CARGO DOOR WAS THE HIGHEST PRIORITY COMPANY DIRECTED DIVERSION TO LBBG REST OF FLIGHT WAS COMPLETED UNEVENFULLY. CORRECTIVE ACTION: PERFORMED MANUAL MODE CONTROL TEST - CABIN PRESSURE CONTROL AMM 21-31 REPLICATED IN FLIGHT EXT DOOR MESSAGES ON GROUND WITH TEST REMOVED AND REPLACED PSEU PER AMM 32-09 PSEU TEST OPS CHECK GOOD NO FAULTS PERFORMED MMLT - CABIN PRESSURE CONTROL SYSTEM AMM 21-31 NO FAULTS OPS CHECK GOOD