What was found
FLT 1265 - MKE-BNA - DURING CLIMB-OUT, THE CREW COULD NOT GET THE A/C TO PRESSURIZE. DECIDED TO RETURN TO MKE DUE TO THE LENGTH OF THE FLIGHT TO BNA. ONCE ON THE GROUND MAINTENANCE PLACED THE PRESSURIZATION SYSTEM ON MEL. MAINTENANCE TROUBLESHOT THE PROBLEM AND FOUND THE DUPM SOLENOID BAD. THE SOLENOID WAS REPLACED, THE PRESSURIZATION SYSTEM OPS CHECKED GOOD, AND THE A/C WAS RETURNED TO SERVICE. (M)