I have a ICE-O-MATIC under counter model ICEU220 this thing has had 3 technicians parts changing on it. The problem is that the evaporator forms ice on the bottom and little to no ice on top. the copper line running into the evap is frozen but the copper line coming out aint freezing. i was concerned about the charge so i recoverd the refrig and weighed in the correct amount. and i still only freezes the bottom of the evap. and its not pulling the suction down to cut in the low pressure control to start the freeze timer. so it dont go into harvest. I checked the water purge valve and its not leaking. I checked the hot gas valve their is a big temp difference. but the the copper line going out of the HGV doesent freeze about a inch and a half . Im thinking a bad txv. but im not sure if the HGV is not closing all the way? Is their a good test to check the HGV or txv?