Question LG 50LB6300 Scan drives?

Mar 7, 2020
The TV is an LG 50LB6300. The picture was flickering on and off, mostly off. Replaced leds. Screen stayed on but there was ghosting in the center and one side was different color than the other and the magic remote cursor would leave trails wherever it traveled on one side of the screen. That was the first day. I happen to have two of these exact same tvs, purchased at the same time at the same location. The next day I brought the working one down to swap parts. Now on this day the screen is completely dark even though the leds come on. I start swapping parts. Nothing has any effect. Eventually I'm able to get some change in behavior. It turns out that if I disconnect one of the ribbon cables going from the T-con board to the scan drive boards I get something. Half a screen of pretty good looking display if I leave the right side connected and half a screen of vertical/ horizontal line mess when I leave the left side connected. If I connect both ribbons again I get black screen again. Any Ideas?