Well, my D5100 didn't come home today. The same thing was happening, only a partial picture if the lens was in manual. Nothing happened when the lens was in A except focus, so it went back with the lens this time.
When Chris saw how upset I was, he suggested we go buy a backup camera. We called a friend and he said the reviews for the Nikon J3 were really good. We pedaled home to get the Jeep and went to Costco. They're on sale for $699. When Chris saw it, he said "that's not a camera". He then pointed to another camera and said "now that's a camera". So I am now the proud owner of a D7100. I still can't believe it. Wasn't planning on getting another camera, but I have one now. The battery is in the charger as we speak. We'll see how things go tomorrow. More learning for me.
Oh, the camera case that came with the camera doesn't fit in my new extra large bike basket, so I guess I'll have to start using the big metal one that goes on the back of my bike.