All replaceable parts in heating circuit test good. (hi limit, thermistor, and heating element) It appears to me ( I am NOT an expert) that the next place to look is for a bad control assembly. I want to make sure that I don't electronically damage the new control board. Do these control boards usually fail internally or is there a danger that a failure external to the board could cause some component on the board to fail when new board connected. I do not want to make a $90.00 + mistake. Please advise. The dishwasher operates correctly through all cycles except no heat to water or air.