I have a D800 that's been having issues with the display turning off a few seconds after boot up. I can get the video if I attach an external display to the laptop. The only way to get the display to come back on is to shut the display for a few moments then open it again. The display will stay on for about the count of five seconds then goes dark. No dimming is noted, nor are there any lines or other artifacts on the screen. The display just keeps turning off.
Recently, I booted the laptop after a long time shut off and the display stayed on. But it has since gone back to it's old ways.
Preceding this I did have issues with the display cutting out while on battery only. I had to have it on AC power to keep it from happening. But now it even happens on AC Power these days.
Any ideas what is causing it?