Intermittent Vertical Lines on Vizio e50u-d2

I have a Vizio e50u-d2 that has intermittent vertical lines. They seem to appear on their own after a few minutes to an hour. They go away if I press on the back of the unit on the VESA mounting holes. Where should I start troubleshooting?

Edit:

So I followed some troubleshooting steps on other posts in this forum. Took off the back cover an reseated the ribbon cables on the t-con board. Now the display is just black where the stripes once were, occasionally flashing white. Pic below.

Both the T-con board and the main board look OK.

What’s next?