Troubleshoot a refrigerator by checking the simple problems, such as the power plug, thermostat setting and blockage on the freezer vents before moving on to more complex issues. Vacuum the cooling coils, and make sure the condenser fan is operating for proper cooling.
While most power cords for refrigerators connect behind the unit to reduce the chances of accidentally unplugging them, if the cord comes out of the outlet the device does not cool. Access the power plug, and check the connection. Plug another appliance into the outlet, and make sure it has power. If there is no power, check the circuit breaker.
Most manufacturers locate the thermostat inside the fresh food compartment. Check the settings for both compartments, and make any necessary adjustments. Use a refrigerator thermometer to accurately determine the temperature.
Make sure frozen food boxes do not block the vent that allows cold air to move from the freezer to the cooling compartment. Move any boxes from the back of the freezer a few inches to give the cold air access.
Dust on cooling coils decreases the efficiency of the unit. Vacuuming the dust sometimes allows it to cool correctly once again.
Remove the cover to the condenser fan, and make sure it is turning freely. If the fan does not work, replace it, and see if the unit starts cooling again.