Hi Eugene
The first thing I would check is the damper itself. Remove the damper cover from the back panel in the freezer and check how it moves when you turn the knob.
Then I would check the position of the cold control sensing bulb.
If the cooling system is low on Freon then it should be warm (not extremely cold) in the refrigerator. Forget about Freon leakage in your situation.
Frigidaire is a part of Electrolux.
- Here are the break down diagrams for the Frigidaire refrigerator
Model F44N18CED1
Good luck.
Gene.