Chosen Solution
I have an A1708 MacBook Pro (late 2016) that just started developing small horizontal lines all the way up and down my display. It started yesterday on the right side of the screen and has now spread all the way across.
I know one of the many open extended repair items for this model right now is for the “FlexGate” LCD flex cable issue. The symptoms are different but could this be related to FlexGate somehow, or do you think this is something else?
Sadly, this is a different issue. In your case the T-CON board which is attached to your display unit has a problem. Given its location within the main case between the heat radiators of the heatsink puts it at risk of overheating. A common cause is when people use their systems on their beds or other soft surfaces so the vents get blocked starving the system of its needed airflow. While its an annoyance you may want to live with it Vs replacing the display assembly. Do you still have an active AppleCare+ support contract? That will help defer the costs in replacing it. Update (03/23/2020) Here’s a picture of the display assembly with the T-CON board attached
It’s part of the display but it sits inside of the main case
And here is the display assembly if you got a replacement:
