What was found
TPA - FLT 984 - ON CLIMB-OUT FROM TPA, CREW WAS UNABLE TO PRESSURIZE AIRCRAFT. FLIGHT RETURNED TO FIELD AT TPA AND LANDED WITHOUT FURTHER INCIDENT. NO EMERGENCY WAS DECLARED. MAINTENANCE FOUND THE CABIN PRESSURE SELECTOR PANEL AT FAULT PER JOB CARD J321-30-10. REMOVED AND REPLACED CABIN PRESSURE SELECTOR PANEL. ALSO, AS PRECAUTIONARY, REMOVED AND REPLACED THE CABIN PRESSURE CONTROLLER (P/N 763810-1). RAN ENGINES AND OPERATED PRESSURE CONTROL VALVE PER JOB CARD. NO AIRFRAME AIR LEAKAGE NOTED. AIRCRAFT OK FOR SERVICE. (X)