I am working on a Samsung un55cu7000d which has backlights and audio. There is no picture. This model does NOT have a separate TCON board. Before I order a main board I would like to try and confirm that the issue is not in the display. The ribbon cable from the main board goes directly to the display and I can then disconnect the left from the right. When I disconnect the right side the display lights up on one side but has no video being displayed. Can you all give me some guidance on how to confirm the main board is the issue.

Hello everyone,
Years ago I was a TV repair tech. I moved on to Cellular Equipment which is the equipment under the local cell towers that our cell phones use. I am now retired and repair equipment for enjoyment....