Thanks Bawanna, but it appears that the crisis has been averted. After I last posted, I decided that I had nothing to lose, so I went up in the attic and began tracing the wiring in the furnace. I found a ground wire that seemed to be making intermittent contact, and I secured it. The furnace has been working properly for four hours, w/o the starting and stopping as before. The tech was going to charge $350 for a new board. I'll pay him for a service call, but I question his expertise since someone with no knowledge of furnaces fixed it.
BTW, the cat is happy now.
BTW, the cat is happy now.

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