Is there a back cover missing behind the refrigerator?
Products with capacity below 290L cools motor by free convection cooling,
and back cover is not attached to enhance efficiency.
How to fix
Cover is not necessary for normal operation.
Those with capacity less than 200L do not have a cover. This is not a defect.
※ Refrigerators with capacity higher than 300L has a fan motor to
cool motor, and has a cover on the back.