What was found
CABIN NR 2 PRESSURE REGULATOR INITIALLY ROUGH DURING TAKEOFF AND CLIMBOUT, EVENTUALLY SMOOTHED OUT. FAULTED AT FL 310. HAD TO TURN BOTH NR 1 & NR 2 OFF & USE MANUAL PRESSURIZATION CONTROL TO RECOVER, EMERGENCY DECLARED, CONTINUED TO DESTINATION. TESTED NR 1 AND 2 CONTROLLERS IAW FIM 21-30-00, NR 1 TESTED GOOD BUT NR 2 FAULTED THE CONTROLLER. PRESSURIZED ACFT IAW AMM 21-31-00-05, NR 1 SYSTEM OPS CHECKED GOOD. ACFT OK FOR SERVICE. REPLACED NR 2 CPC IAW AMM 21-31-11-04. OPS TESTED GOOD.