I made sure the defrost cycle was selected, and nothing happened, the frost continues to grow (damned fast this time). I gave it a day and a night after I selected defrost, because the semi-clear instructions on how to do so suggest it needs that much time. I know it was enabled because one selected, the unit’s sound changes. I’m looking for something to let me measure the ohms. I’ll look at the manual when I get home to see what the parts to be measured look like.