lg 86” turns on briefly then goes black. Backlight still on

Hello, I have a Lg 86um8070aub smart tv. was working fine and the kids were watching tv and the picture just went out. Now when I turn the tv on the logo appears for a few seconds with lines running horizontally on the top and bottom of the screen then completely fades to black but the backlight is still on. When I first start it I can hit the Netflix button on the remote and the app will start then freeze and again fades to black with the backlight on. I tried unplugging it and holding the power button down and all the other basic first checks you find online but nothing has helped. Any ideas? Thanks for any assistance!