My Samsung 4k UHD and Apple TV are not working. How do I fix it?

I have a Samsung 58" NU8000, 4k UHD television and a 4k Apple TV (4th gen). I have been trying to get them to work for some time now. The Apple TV just randomly starts blinking and the screen goes black. I have checked the forums... in numerous places... and have tried WAY TOO MANY things for these 2 items to work. I have changed cables. I have reset the TV and the Apple TV. I have changed out the TV box that you plug all the USB and HDMI cables into. I have taken the cables out and changed which HDMI port it is using. I have changed the settings on the Samsung TV to recognize the Apple TV as HDMI port 1. I have taken the Apple TV to the Apple store and had it replaced with a new one. I have turned off the Autoupdate feature; turned it back on... I still end up with the same results... flashing Apple box... with no access to all the money I have put into Apple movies, etc.