|Here's a download for the manual in case you don't have it:|
(The nikon site kept shutting off the download.)
It looks like it has a separate battery for the clock function and probably to hold the other settings, which is where I thought the current was flowing. That makes an even stronger case for an internal short. Barring something like a dirty battery compartment or a battery issue (which doesn't seem likely) you'll have to concede your camera is broken. You can't push a button or change a setting and magically fix it. We can't clairvoyantly look inside and see what's going on. I don't know what more you expect.
Well you can try giving it a whack. That sometimes fixed my old TV.