I found out that I had two things go wrong with my freezer so it was more complicated than just fixing a single problem.
Did some studying of the cases on the Appliancepartspros website and came to the conclusion it was probably the controller so I ordered one and easily installed it. I could tell by the lack of beeping, plus the controller was now able to adjust the temperature on the panel. Couldn't adjust it before, was stuck on 3. After running several hours the temperature inside was still a bit too cold with the controller set at 1. More studying in the website, looking at videos and calling Appliancepartspros I came to the conclusion I had another problem besides the controller - the thermistor. I replaced it easily but even at 1 the temperature was almost at the coldest point so it was working but giving the wrong signal to the controller. The manufacturer's recommendation is to set it at 4 which would have set the temperature at the coldest in the range.
I called Appliancepartspros again and they were kind enough to send me another thermistor which I easily installed.
Now it works perfectly! I recommend this company without reservation. They are friendly, their parts prices are reasonable and they are easy to deal with!