I have a MacBook Air 2020 M1 which developed a screen issue. In the beginning the display only worked with the lid a few degrees opened. It worsened while troubleshooting, to a full black screen. External display works fine as long as the lid is closed.
I replaced the screen with no effect
I replaced the Flex cable with no effect
I replaced the speakers with no effect.
I put the MB under the microscope and detected a blown component, related to camera I believe. It might have taken out the UP700 above as well?
Mac itself boots...