I just checked my SB600 and it would not turn on. I haven't been using it much lately--using my SB800 instead. But the SB600 did see some use last week and it was working. Naturally I looked at the batteries. I did notice that one (regular alkaline) battery had leaked a little bit. Just enough to leave some whitish residue at the top and on the cover contact.
After cleaning it up with a soft brush, I replaced the batteries with 4 Eneloops (white), but still nothing. Just to be sure, I took the 4 Eneloops from my SB800 --which I know is working fine-- and put them in the SB600. Still nothing.
Any ideas on what may have happened?? I'd appreciate any assistance or advice. But, of course, I can wait until tomorrow as I suspect quite a few us us Nikonians will be busy digesting Turkey today rather than talking Turkey!