The unit is not that old, but it has been icing up behind the cover at the back of the freezer which does not allow the refer to stay cool , I have been melting the ice which works for a couple of weeks but now the cycle is happening more often - do I need to get another motherboard? Defrosting element?
Thanks

You have to thaw out the freezer and remove rear cover. Test heater element and see if it is burned open. Test with an ohm meter. If it has no continuity then it is bad. There is also a defrost terminator with one wire going to heater and other wire going to defrost timer. Unplug it and put in a freezer and get it below 32 degrees. At that temp the t-stat should close and you should read zero ohms. If not replace it. If either of these are bad replace the bad part and your problem should be solved. I am not familiar with the defrost controls on that model, but if it is electronic the odds are slim that it has failed. DrTom4444