@waltthompson you are not giving us much to work with here. We do need to know what model your TV is. Returning a quick and dirty answer based on the information we have, this is not a board issue but a backlight issue. Your strips are turning off, cooling down and then coming back on. Replacing the backlight strips will resolve this. Sometimes you can determine if it is the strips by decreasing the brightness of the screen. If you set it to 50% or so and it stays on longer , you know it is the strips.
Now, this answer may change if more information becomes available.