No, I haven't had to as of yet, and I've replaced a lot of those boards. As long as the heater comes on in defrost, I just replace the board. That saves you from needing to ohm out the heater and the defrost bimetal. Plus it makes thawing it out faster. It may take a few minutes for the defrost to come on. Usually, by the time I get the freezer apart, it's already hissing and popping away as it melts the ice.