Thank you all. I tried everything and gave up. UPS picked it up yesterday for delivery to Nikon today. Hoping their turn-around is quick.
Thanks all for the help, and thank you Paul for the generous offer.
Dave in NJ
As previous posted, I would try a battery removal, you can also reset all the current settings back to factory default. I don't have my manual in front of me, but can look it up later. I had a freeze on a
D800 similar to yours that this fixed.
As for the cards, in theory you should be OK, as the Sony should just create a new folder, however I would not risk it if the images are important. I have had a problems moving between various Canon bodies, namely a 5D MKII and 1D MIV. That's another story and I was able to get the images back, but it a bit of a shock.
Can you order/purchase new cards? Not sure if in your location they can deliver or not.
If you need a card, I can send you one, as I have quite a few 16GB laying around unused at the moment.
PM me if you need to.