Why isn't ice forming in the freezer of my mini fridge?

Question

It use to freeze with a layer of ice over the box during my first semester at school. It was unplugged and defrosted to take home, then when I brought it back to school and plugged it in- the freezer didn't ice up? Does anyone know why this happened?

Answer 1

Because it is not self defrosting, you have to defrost it manually.  

Answer 2

Because they suck.Basicly when you move a fridge you s***w everything up I can go into detail but I'm not.If it is that big of a problem buy a new one.