[mata2mata]

I have a GE Monogram ziss480dxass (ZIS480DX says the Technical Date sheet in the unit) that stops cooling every 6 to 10 days. I got this unit from my brother who remodeled his kitchen. The unit says manufactured 2/09, this makes it under a year old. I installed it and noticed that after about 10 days running the temperature on the refrigerator side started going up until it was 59F. I then noticed the air vents were not blowing in the cool air at all but a room temperature kind a soft blow and same thing on the freezer side. I removed the Ice tray, stock my hand into the vents right above over the ice maker and noticed the evaporator was frozen. Since them all I do every 6 to 10 days, after the cooling stops again, is turn the unit off, use a hair dryer and a fan to blow air into the evaporator through the vent holes above the ice maker until water starts flowing through the drain hose. After all the water is drained from the frozen evaporator (which takes about 3 hours with the fan running into the freezer) then I can plug the unit back and wait for normal temperature (1F freezer 37F refrigerator) to go back. Then I get to do it all over again within two weeks.
This I understand is a problem with the Defrost Heater not going on. It could be the Control Board (sort of computer) or the Defrost heater itself. I tested the plug going into the heater for continuity and got none. My next step is to get into the evaporator and replace the defrost heater.

Can anyone tell me if this should be my next step and how do I get into the evaporator without having to remove a million parts. Is the heater replaced from inside the freezer or outside? How do I get to the evaporator unit? How do I further test the heater without removing it? Thanks