This is the most bizzare thing and I just wondered if anyone else has ever faced the same problem.
I adjusted some of the picture settings on my 60" F8500 last night but now whenever I select those settings (e.g. movie) and exit out of the menu the picture slowly gets darker and darker. Not totally blacked out but very low contrast/brightness. In fact, if I just select just about any of the settings (other than dynamic) (e.g. standard) and then exit out of the menu, the picture gets darker and darker slowly over about 30 seconds. But, if I go back into the settings and select the dynamic setting then suddenly they're back to normal. The problem is that it won't hold any of the settings after I exit the menu, except for the dynamic setting. For some reason it holds that setting but not the others.
I went back and did a factory reset, but still seems to have the same problem. I also unplugged and rebooted the TV. Very weird. Any idea what I might have done to cause this?