Open the freezer door.
Remove all food items from the vents in the freezer wall. Wait a few hours to see if the freezer begins to cool. If not, troubleshoot further.
Open the freezer door. If the refrigerator sounds noisier with the freezer door open, you may have a faulty fan.
Unplug the fridge from the wall. Open the freezer and allow it to thaw.
Remove the screws from the back panel of the freezer and remove the panel. Be careful not to break any of the plastic moulding.
Tighten the screws around the fan to tighten it to the refrigerator wall. Plug the unit back in and wait for the fan to start. If it is still noisy, replace it.
Remove the screws from the fan. Pull on the wire connector to unplug the fan. Plug the new fan in and secure it to the back wall. Reassemble the freezer.