Just got a 70 inch TU7000 series TV from target a couple of weeks ago. It's had a couple of odd issues, and I'm beginning to suspect it's from running out of memory from heavy caching.
One morning the TV turned on to have a light/neon green overlay over the image, even over the menu. Opened the menu to rule out it not being an issue with the source which was Samsung TV broadcasting. The only fix was to unplug the power cable for a few seconds and then plug it back in. A normal power off and on didn't resolve it, so I did a full power removal.
Last night, after watching videos on youtube for several hours, the screen began to strobe like a strobe light. It progressively got more intense and then the TV restarted, powering on to the Samsung TV app. We don't have any external devices connected, just use the built in OS for Youtube, Plex, and Netflix. We're connected to Wi-Fi. Standard US power, and nothing funny in between.
I do use YouTube a lot, and I suspect it's running out of cache memory. It's been fully up to date on system software. Eco power settings are disabled. Advanced motion settings are disabled (don't like the weird "fluid" look anyway).
Any ideas, or do I have a lemon?
I recommend letting a service technician have a look. Send your full model code and serial number via private message to get started.