Where does screen graphic cable connect?

Sorry to be late getting back. After months of nothing, things are getting busy again!

If by display angle you mean that discoloration does not happen across they screen,

To clarify, I meant doing an opening/closing movement of the display unit. That "wiggles" the cable a bit and any defects in the cable will show up as flickering or moving defects artifacts on the screen when you do that. When I test that way, I start with the display at approximately 90° to the keyboard and then slowly move it about 20° forward and back, watching the display as I move it.

I do not see any open Apple warranty extension programs for your model. As your MBP has a "Retina" display, the display unit, the cover glass, outer top case, and cable are all one integrated unit and cannot be separately replaced.

From what you've provided (well done, thank you) and knowing how service-unfriendly newer MBPs have become, I believe you need to have Apple continue any evaluation. I cannot find a logic board diagram for your specific sub-modle that gives me the confidence to tell you where the display cable connects to the board. Although I have a suspicion where it is, I'd rather not guess when it is someone else's computer.

In internal views of otehr 13-inch Retina MBPs, the display cable is secured to the logic board with screws, If yours is as well, that takes a loose cable connector off the list of suspects in my book.

Time to talk to Apple.

The video cables are secured with a bracket & screws so it is highly unlikely it is loose at least on the connections to the Logic Board. If there is a video cable failure or an LCD failure on the USB-C laptops, then it requires the replacement of the whole display assembly which is not something a regular user should try replacing (even experienced techs find this repair annoyingly difficult).

No idea without knowing your MacBook Pro sub-model.

MBPs have been around since 2006 in many variations, and connector locations have bounced around over the years. You can find the sub-model by doing "About this Mac.." from your Apple menu:

Cable issues like you suspect very often will cause changes to the on-screen image when you change the angle the display, If you don't see that, it not too likely to be the cable.

A more effective diagnostic is to connect an external monitor.

• If the defects do not show on the external, then the suspects are the display itself, the inverter, or the cable.
• If you see the same defect on the exernal as on the built-in display, then the issue is the video hardware which, being integral with the logic board, cannot be fixed without changing the entire logic board.