What was found
AT CRUISE ALTITUDE CABIN INFLOW LOW MESSAGE CAME ON QRH PROCEDURES FOLLOWED AND DESCENT TO FL 24.0 WA BEGUN. CABIN CONTINUED TO CLIMB W/OUT FLOW, VALVE CLOSED DURING DESCENT. CABIN ALT REACHED 12,000 AT MAXIMUM. DESCENT CONTINUED UNTIL CABIN BELOW 10,000'. LATER DURING FLIGHT CABIN INFLOW LOW MESSAGE WENT AWAY, MANUAL PRESSURE WAS USED AT A/C ALT AT 11,000. REMOVED AND REPLACED NR 2 CPC.