Built-in display black screen coinciding with Big Sur update?
I have a 2018 Macbook Air that recently had Big Sur installed on it. I’m trying to figure out whether this issue was caused by the upgrade, or if a hardware issue just happened to coincidentally manifest within the same week.
Last week, I upgraded from Catalina to Big Sur. The installation went fine (no issues getting stuck at black screens as others have reported with some models), but afterwards I noticed that Touch ID was no longer working. I didn’t think much of it at the time, so continued to use the device.
A few days later, I finished up working and closed the laptop. The next morning, I powered it on, but the built in screen remained black (but with a back light): no Apple icon, no text, nothing. For several hours I thought that the device was completely dead. I tried resetting the NVRAM, the SMC and booting into Recovery and Network-Recovery modes but still no video on the display.
I then found a post about enabling Voice Over. Sure enough, pressing Command + F5 started voice over and it read “Username.” This indicated to me that the laptop was booting correctly, but the display was not working. After entering my username and password, I then plugged in an external monitor that I have. The external monitor came on and displayed video.
From within macOS, I am able to see that both displays were detected (via System Information as well as Displays).
- No video on built-in display, even during startup.
- Dimming and brightening works via keyboard shortcuts.
- Can boot into macOS using Voice Over to navigate.
- Built-in display is detected in Displays and System Information applications.
- External monitor displays correctly.
Does this sound like a hardware or software issue? Should I attempt to downgrade from Big Sur back to Catalina?
Edit: I just tried opening Photo Booth to test out the camera. The green light comes on, but no video appears to be captured from the camera. The camera does appear in System Information > Hardware > Camera however. Do the screen and camera share the same cable?
Edit: While playing around with opening and closing the lid, I noticed that the camera does indeed turn on momentarily when the lid has just opened up (around the time the laptop would register the external monitor as a second display) but then immediately turns off once the lid is opened a little more. As mentioned above, the green indicator stays on even when the camera itself no longer appears to be streaming video.
Edit: I have since reinstalled Catalina, but the device is still exhibiting the same issues. The fact that the camera will turn on just after opening the lid but then turn off again makes me wonder if the issue is somehow related to the lid-switch mechanism.
Is this a good question?