I have a small Beverage Center fridge made by U-Line. It suddenly completely stopped cooling. It is still running but it is room temp inside. I took the back off and the compressor still runs and is warm. The condenser coils are at room temp and are clean. Just wondering what to check as don’t want spend $300 on a repairman to tell me I need a new one.

It did indeed lose its gas. I actually found someone to take a look and he repaired it for a fraction of the cost of a new one (they're over priced). It cools but now I noticed that the temp inside the refrigerator varies by quite bit. I put a thermometer in it that has a min/max feature. The max will be around 43/44 F and the min around 27/28. So it cools until it reaches about 27, then waits to cool until it reaches 44. That seems to big a gap to me. Not sure if it did this before it was repaired. Someone told me that could be too much gas put in by the repairman?

I should have mentioned. I had already replaced the t-stat and no change.