And sure enough...
Opened her up tonight and saw the broken wire. I was expecting to see it hanging off but looking at it from a different angle showed it better. It WAS hard to see because it just looked like a section of it was broken out.
Anyway, I am another who has performed the repair and voila! Back in business. Of course, it took me about 3 hours - slow, deliberate, careful.
Great thread, great job pointing out a common design flaw.
p.s. I think that one of the three wires is not connected for anyone who gets either full cold or full hot with no switching as that happened to me and replacing the wires was my fix. Not an expert but that is what worked for me.