Hello. I have an Amana ABB2524DES with the evaporator freezing up. It takes about two months from me manually defrosting the coil to the fridge losing it's cool. The defrost thermostat shows closed when I do a circuit test on the control panel and the heater gets hot. the heater has 27.5 ohms of resistance. I am able to enter forced defrost mode and do a short run period test which lasts about 15 minutes. During this time the heater gets hot but won't melt the totally frozen coil(probably normal). It seems to me from reading this thread that two months is a long time in between manually defrosting, so I wonder if the defrost circuit is working sometimes or marginally. The element gets hot but it doesn't glow at all. Is there something else I can test before I replace the control board, it doesn't feel right to condemn it since all service tests and modes work properly. Thanks for any help and for this site.