Ice buildup inside Samsung RF266 refrigerator
Had same issue with my Samsung refrigerator for a while was defrosting the fridge to work but was lucky to find repair kit for this issue and now not icing anymore for over 4 months now so decided upload my recommendation here.
please use link to view the lifesaver kit :)
Samsung Refrigerator Defrost Booster Kit -Ice Buildup, Noises and cooling issues repair kit, Samsung ice buildup repair kit
good luck guys