Chosen Solution
the flex of the screen was damaged and I want to disconnect it to use it with external screen as main, who can tell me which is the central flex of the screen?
First alter the display primary screen using the Display preference setting with the external connected. See if you can get things working by using either a USB or Bluetooth keyboard and mouse/trackpad. Then just close the display the system should realize the screen is the external and just use it. Otherwise there is no means to alter things, and you can’t tap the internal displays connection. While not cheap replacing the display is not overly hard MacBook Pro 13" Touch Bar 2017 Screen Replacement and here’s the needed part both are used Grade-A: 3” MacBook Pro Display Assembly - Space Grey, Apple P/N 661-1003713” MacBook Pro Display Assembly - Silver, Apple P/N 661-10357
