This is a widely reported issue and now it’s happened to me.
My 58 inch UN58TU7000FXZA will not power on. It just does a constant power cycle where the backlight comes on then goes off again. Tried unplugging all cables (HDMI and power) and using different outlets.
It tries to turn on, we see the backlight for the screen flicker (but no graphics or menus appear), and then the TV powers off. I can see the red light in the bottom right corner of the unit indicating the power is off.
TV was purchased in Dec 2020 so it’s out of warranty. This is obviously a widely reported issue so I hope Samsung has a solution to fix it since the TV is defective.