Chosen Solution
My laptop screen just went blank/black, but it still works fine if I connect it to my external monitor. What’s seems to be the matter with my system?
I would suspect the display cable has failed. This is a known issue with the 2016-2019 USB-C model laptops commonly referred to as “Flexgate.” Apple has a service program that I would recommend taking advantage of if you can. The service program only officially covers one two 2016 models, but the same design defect is known to be present in the 2017 models. Here is the link to the service program. It may also be worth contacting an Apple Authorized Service Provider and talking to them about the issue.
