What was found
ON CLIMBOUT, AIRCRAFT DID NOT PRESSURIZE. PERFORMED ABNORMAL, AUTO CONTROLLER WAS INOPERATIVE. UNABLE TO CONTROL PRESSURE. INSPECTED ALL ACCESS DOORS, ALL CLOSED. INSPECTED AND LUBRICATED OUTFLOW BUTTERFLY VALVE LINKAGE AND OUTFLOW NOZZLE, NO DEFECTS FOUND. MANUALLY PRESSURIZED AIRCRAFT, ABLE TO GET UP TO 3.3 DIFF PRESSURE. REPLACED THE AUTO PRESSURIZATION CONTROLLER IAW DC-9 MM 21-32-00-2-0601. OPS CHECKED GOOD.