How can I fix my dehumidifier?

I have a Whirlpool Model AD50USL4 Dehumidifier. It stopped collecting water. A local service repair person said that in most cases it is a bad insulation around the Restrictor Tube. I wrapped the Restrictor Tube in new insulation, but still no water collection. I wrapped the Restrictor Tube completely around isolating it from the Compressor. Was this a mistake? I also noticed that the Compressor was very hot to the touch right after I turned it on. Is that normal? Also tubes did not seem to change temperature. Are there any other problems that I should check for, such as lost coolant?