completely frosted. In fact, it's blowing "snow" all over the freezer. It doesn't normally do that.

Ok, I replaced the motherboard but it would not manually defrost. I put the old one back on and it won't manually defrost either. How do I isolate which part of the defrost has the problem?

And just as a side note because I'm trying to understand how it all works, so even though the freezer isn't frozen over (as it has sometimes been in the past since) because I defrosted it last night with a blow dryer, shouldn't the refrigerator section be cold and working normal until the icing of the freezer happens? I thought the cold air was supposed to blow up into the refrigerator once the defrosting is complete, but maybe I'm not exactly understanding how it's all supposed to work. Anyway, thanks again for all your patience and help. At one point I considered maybe getting a new one, but there really is something satisfying about fixing it yourself (with an experts guidance.)

How do I check it?

Ok, not to sound dense, but I'm not exactly sure where to look for that. On this diagram, would it be somewhere on #826? If not, where should I look for it?

Cabinet replacement parts for General Electric GBS22HCPAWW Refrigerator | AppliancePartsPros.com