What was found
KUL - ON CLIMBOUT, NR 1 PRESSURE CONT FAILED, NR 2 PRESS CONT COULD NOT CONTROL CABIN. IAW ECAM PROCEDURES SELECTED MANUAL CONTROL, UNABLE TO STOP CABIN RATE OF CLIMB/DECENT. CABIN PRESS DISPLAY ON ECAM SHOWED OUTFLOW VALVE NR 1 AFT CYCLING RANDOMLY. EME DESCENT ACCOMP, TURNBACK. SWAPPED NR 1 AND NR 2 AFT OUTFLOW VALVES, PERFORMED AUTO AND MANUAL CONTROL TEST ON BOTH SYS IAW A-310 MM 21-30-00, ALL TEST NORMAL. NR 2 CABIN PRESS SYS CONSIDERED INOP DUE TO OUTFLOW VALVE FLUX. DEFERRED PER MEL 21-44 CONTROL NR 0904005 CAT 'C' EXP 9-14-95, MXP C/W SYS NR 2 REG DEACTIVATED. REMOVED AND REPLACED NR 1 PRESS CONTROLLER AS PRECAUTIONARY MEASURE, CONTROLLER BITE CHECK NORMAL.