My old Frigidaire refrigerator doesn't get cold enough in the refrigerator section but is fine in the freezer?

This is the same question I asked last week but these assholes at yahoo deleted it without explanation. My old Frigidaire refrigerator doesn't get cold enough in the refrigerator section but is fine in the freezer. The previous answer involved servos which control the vents or something. Can someone help me to locate the servo, and its relationship to the coldness controls in the front and rear of the fridge? Thanks