GE side by side is not staying cool

My GE side by side refrigerator freezer will not get cold. It is cool, but not cool enough to cool sodas or freeze ice cream. It seems to be colder towards the bottom than at the top. If I unplug it and let it sit for several hours and replug it in, it gets cold for a couple of days then it begins getting warmer.

Replace the motherboard. If it seems to be freezing and thawing in the freezer, replace the motherboard and evaporator fan motor.

Before replacing the motherboard,pull the back freezer panel and describe the frost pattern.