GE Side by side defrosting problem

[tcape]

A friend called me over and his evap coil was frozen making the fridge section too warm.

I thawed it out with a heat gun and told him he will probably need a board.

I checked the resistance of the heater, and it wasn't "open" but my resistance was way higher than I would have thought, if I recall it was like 17m ohms.

What should a good heater ohm out at?

Is there any way other than just swapping parts that I can use to troubleshoot the motherboard?

I sure hate having to swap parts, not knowing for sure.

I'm assuming the defrost thermostat just tells the board to turn off the defrost.

any help would be appreciated.

Thanks

Model GSS22QGPCCC