What was found
AFTER TAKEOFF THE ACFT DID NOT PRESSURIZE PROPERLY, THE PILOTS ATTEMPTED TO RESET THE PRESSURIZATION CONTROL SEVERAL TIMES THEN THE DECISION WAS MADE TO DIVERT FOR MAINTENANCE. A TECHNICIAN WAS DISPATCHED TO THE ACFT & ICY SLUSH WAS FOUND ON THE LG SQUAT SWITCHES WHICH WAS BELIEVED TO BE FROZEN. THE TAKEOFF WAS A FRESHLY PLOWED RUNWAY WHERE SNOW & SLUSH WERE PRESENT. THE ICE WAS CLEARED & THE SWITCH WAS ACTIVATED, THE SYS WAS OPERATIONALLY CHECKED & THE ACFT WAS TAKEN FOR A MX CHECK FLIGHT WHERE THE SYS FUNCTIONED PROPERLY. THE AIRCRAFT WAS RETURNED TO SERVICE.