I purchased a chest freezer about 5 years ago that already had the conversion done using the Ranco ETC111.
I had no problems with this in the past 5 years and all of a sudden (well in the last 2 months) the unit failed. I didn't notice this as I haven't drank any homebrew from the keezer in 2 months. Went to open the thing last week and it was pretty nasty in there.
Setting on the Ranco was for 38, but the probe read 52. I removed all the beer, unplugged the freezer from Ranco and into the wall and the compressor kicked on within a minute.
When I have the freezer plugged into the Ranco the light is on the freezer but the compressor doesn't kick on.