Generally the fridge is plugged into an outlet in the fridge compartment, not hardwired. Quite often this outlet is one of the GFCI protected outlets because it's in a compartment that's more or less exposed to outside dampness.
There may be a fuse for the AC circuit in the fridge. It's also possible that the heating element burned out. I guess what I'm trying to say is that you should do some basic troubleshooting before automatically assuming the board is bad if it turns out not to work with a proven good AC supply.
My first guess would be that it's just not getting AC power.
