This could be caused by several issues:
1. The compressor has a fan by it that blows across the coils. If this fan is not turning it will need to be replaced. If the fan is blowing, check the coils and make sure they are not clogged up with dust or hair.
2. The electronics on the compressor are bad and the compressor is not running. There is a start and run relay on the side of the compressor that burns out and the compressor will not run OR it will click every few minutes like it is trying to start.
3. There is a leak in the sealed system. There are two seperate coils in your unit but only one compressor. If this compressor has low or no freon, is will not cool. This is usually determined by the compressor running, the fan by the compressor running, the coils clear of obstruction and the inside fans working on both the freezer and refrigerator side.
Check all of those things out and let me know what you find. Maybe we can narrow it down to a cure for you.