Chosen Solution
Hi all, I have a Samsung tv (UN70NU6900FXZA) that started power cycling with just a black screen, nothing comes on and just continuously cycles. I opened the back and everything looks fine, and I found a temporary fix…. if I unplug one of the two FFC cables from the main board, unplug/plug power cord, then plug FFC cable again, then the TV comes on. Only problem is, as soon as I turn off the TV and power back on, the power cycle starts up again and I have to re-do above steps. To note, I purchased a brand new main board and the same issue/solution happens with it too. Any ideas what it is? FFC cable issues?
Muayad Al-Yasin could be a cable issue but it’s unlikely. First you need to tell us which ones you disconnected. The reason why it power cycles is most likely because it fails its POST due to a failed component/board. Remove the back from your TV and post some good pictures of all of your boards and the interconnect cables. You need to check the voltages on the power board connector to the main board. Let us know what the results were. Also, you are saying it comes on when the cables are disconnected but you are not telling us if you ever get anything showing on the screen. Concern with connecting the ribbon cables is that this separates the display panel. If it stops the power cycling when you separate the panel, the issue could be the panel. Take some good pictures of all the boards and the interconnect cables and post those with your QUESTION. That way we can see what you see Adding images to an existing question
