When initially trying to increase the temperature in the refrigerator, the belt connecting the control knob to the damper at the back of the fridge broke. I thought this was the problem, but after taking the covers off, I noticed that the damper control was frozen open due to items being placed in front of the cold air vent on the top shelf. I emptied both the refrigerator and freezer, turned it off and let everything thaw out for a few hours. I thoroughly cleaned the damper and replaced the broken belt. Problem solved.