Samsung TV model UN49KU7000FXZA. HELP

@hunt3r0b disconnect the main board from the power board. See if that stops the blinking and if all of your back lights come on (which should). You can see the backlights through to holes in the back of the panel. This could be an issue with the power board (since you said the red light would not come on) it is also possibly a T-con error or, like was mentioned already, a bad panel. Post a couple of good pictures of all of your boards with your question. That way we can see what you see.

Adding images to an existing question

I have the same model of Samsung TV with the same issue that you described. I’ve exchanged the motherboard and power supply for the ones I got online, but the problem persists. My last option is to follow the solution Philip introduced to you. Did his method resolve the issue?

UPDATE:

I owned the same model and had the same problem. And I fixed it by replacing the LED Backlight Strips. You should try it if you haven’t thrown out yours.