Go to the back of the fridg., pull off the motherboard cover, unplug fridg, and unplug the 4 pin power connector. Check pc board for pins labled line and defr. Stick a jumper between these two mating pins on the connector. Fridg should now defrost. If so, replace the motherboard and both freezer and evaporator thermisters. If no defrost, you probably have a bad defrost thermostat, or heater, just check.

Well, I thought that we had fixed the problem when replacing the bad heater. This morning it wasn't cooling and the coils are all iced over again. Wife is thawing them out now with a blow dryer.

I bought a little electrical tester and I have continuity through the heater. What a pain in the @ss this is turning out to be.

richappy, I read your post. If the fridge is unplugged, won't it defrost anyway?:confused:

I tried to follow Gene's sticky post but my thermostat doesn't have an adjustment on it. But it may be screwed up. It's a metal cylinder with a blue plastic piece fitted in it. The blue plastic was in it crooked. When I straightened the plastic piece and pushed it into the metal some water came out. Maybe this was the issue?

Thanks for the quick response. It looks easy to do except for one thing... I can't figure out what I need to remove to get to the connection for it. The thermostat intself simply snaps on to a coil. But the leads go somewhere and I'm not sure where and what I'll need to take off to get to the connections. Any advice on that? Again, thanks a ton for the help.