How can I fix my Samsung RS21NCSV?

Ice build up, in the back unit inside the fridge, Could be faulty sensor or defrost heater etc, thats If it does not stop doing it.
Next defrost cycle, noise will stop, If it does not, as above faulty part, as unit not defrosting. Depending how long you have had the unit, Samsung did bring out some modifications, the defrost heater was found to fail. You would need to remove the inner back panel, careful with the plugs, just as you start to move the panel, they need unplugged. then sensors on the heater element need to be checked as well as the element itself, You need a test meter, and need to know what you are doing, If not get some one in, New element, was about £70 which included a new evaporator coil as well, which is not needed. Sensors afew£

SD
August 2011