There may be various reasons why the mini small refrigerator does not cool. Here are some common reasons:

1. Fluorine Leakage: If the refrigerator's cooling effect becomes poor, it may be caused by fluorine leakage. If there is a leakage of fluorine, it will not provide enough cooling, resulting in the refrigerator not being able to maintain its temperature. Check your refrigerator and look for any signs of Freon leakage, if you find a leak you need to call a professional repair person immediately to fix it.

2. Improper maintenance: If the refrigerator has not been maintained for a long time, it may result in poor cooling. Keeping the refrigerator dry and clean and regularly cleaning the back of the refrigerator of dust and dirt can help maintain good cooling.

3. Incorrect temperature settings: The refrigerator may not be able to achieve the desired cooling effect because the temperature setting is too high or too low. Check the temperature setting of your refrigerator and make sure it meets your needs.

4. Internal malfunction: Having an internal malfunction can also be the reason why the refrigerator fails to cool. It could be due to faulty parts like evaporator, circulation fan or motor. You need to seek the help of a professional repairer and make the relevant repairs.

In summary, there are various reasons why mini mini fridges don't cool, and proper maintenance and care is very important to prolong the life of the fridge and keep it cooling. While there are a number of issues that can be resolved by the consumer, it is still recommended to seek professional repair help when necessary.