Update:
I finally got a couple of genuine Olympus C-7AU power supplies off of eBay, and the camera seems to work just fine now. I also got a second camera and it also works fine with the Olympus ps, but not my generic 6 vdc bricks. Apparently these cameras a fairly finicky about the supplied voltage, and/or I just got unlucky with the bricks I had laying around the house. Anyway, my weekend project is to get the cameras online full time after some upgrades to my dedicated 24/7 Weather PC.