What was found
AT FL 320, AFTER LEVEL OFF, RIGHT PACK PRESS DROPPED TO 0. COMPLIED WITH QRH 21-5. CABIN ALTITUDE CONTINUED TO CLIMB, DURING DESCENT, CABIN ALT WARNING LIGHT ILLUMINATED. COMPLIED WITH QRH 21-2, PAX O2 MASK DEPLOYED. PERFORMED TASK CARD F0443601, NO DEFECTS NOTED. PERFORMED VISUAL INSPECTION OF BOTH LT & RT PACK, OUTFLOW VLV & SURROUNDING AREA. ALL EXTERNAL PITOT & STATIC PORTS, AOA VANES & TAT, NO DEFECTS NOTED. PERFORMED DFDR DOWNLOAD PER TC A0573101. REF LP 53433 FOR SENSORS S1-120, S1-122 & RELAY R2-148, R & R. OPERATIONAL CHECK OF NR 1 CABIN PRESS CONTROLLER IAW MM 21-32-00. OPERATIONS CHECK NORMAL. FAULT HISTORY SHOWS NO FAULTS AT THIS TIME. OK FOR RETURN TO SERVICE. THIS CLEARS MEL 21-24, SIT 1, DMI 13404 PLACARD REMOVED (M) PROCEDURES BACK TO ORIGINAL CONFIGURATION. REMOVED AND REPLACED SENSORS S1-120, S1-122 & RELAY R2-148 IAW AMM 21-31-05 & 24-00-00 PRECAUTIONARY. OPERATIONS CHECK STILL REQUIRED IAW LP 534304.