What was found
DURING CLIMB ON, THE CABIN WOULD NOT PRESSURIZE, STOPPED CLIMB AT 10,000, CAB ALT WAS 10300. DELTA P WAS 0.1 COULD NOT CONTROL THE CABIN PRESSURE IN MANUAL OR AUTO.(<P>REMOVED AND REPLACED R/H OUTFLOW VALVE IAW B747 AMM 21-31-01 UP TO SUBTASK 21-31-01-430-016. OPS CHECK GOOD.</P>)