iFixit has been working on a story about the display ribbon cable in the Thunderbolt 3 MacBook Pros. Here’s the gist of it:
The issue is fairly simple: the current generation of MacBook Pro laptops (2016–present) uses flexible ribbon cables to connect the display to a display controller board beneath the Touch Bar. These cables wrap over the board, where they’re secured by a pair of spring-loaded covers—and they’re subjected to the stress of bending with every opening and closure of the laptop. Within a seemingly short time, those cables are starting to fatigue and tear. The backlight cable is generally the first to go, producing the infamous “stage light” symptoms, and eventually giving out entirely when the laptop is opened more than about 40°.
The “stage light” phenomenon is not what that I have seen in the wild, but having your notebook’s backlight fail is a real pain if you like using the display. In the meantime, the 2018 MacBook Pro seems to have been tweaked to avoid the problem. Again, iFixit:
However, when MacRumors user Olivia88 noticed their 2018 13” MacBook Pro seemed to have a longer cable than previous models, we were intrigued. Since we were just wrapping up writing the repair manual for the 2018 model anyway, we checked inside our 2018 15” MacBook Pro again to measure its cable against its 2016 predecessor—and found the 2018 cable was, in fact, a full 2mm longer. Since this change appears in both our 15” model and Olivia88’s 13” model, it’s plausible this change is present in multiple, if not all, 2018 MacBook Pros.
That’s good news. Apple has not commented on the issue, but I expect the company will open a Repair Extension Program if it ends up being widespread.