I do alot of electical work on the side. Did you check to see if you have a power to the unit/ You would be surpised how many loose or broken wires I find. A meter may save you alot of money. Does the unit even turn on? Another spot to check is the relay on the unit. No power is for the most part is an easy fix.
Prime I'm no expert but just past exp. One if you have a dual voltage unit the converter could have went bad or loose wires as said above. Also depending on the age some have a reset button on the converter Also I had one that had a bad thermostat and belive it or not on realy cold days it would shut itself off. Just in the event you were trying it in extreamly cold weather. Most likely the converter or broken or loose wires as said above.