Has anyone else experienced the inability to mirror retina display to external monitor? I can extend the desktop, but I can't mirror it anymore. Screen flashes mirrored, and then flashes back to extended view. Used to work in Sierra ...
MacBook Pro (Retina, 15-inch, Late 2013), macOS High Sierra (10.13.1)
@Bob: same monitors (multiple different ones) including a 24”IPS that displayed full 4K resolution before High Sierra ... it worked before the update with the same setups ... monitors work as extended displays, and I can change retina and external monitor(s) to be the same resolution ... they just won’t mirror ... (and they used to before I upgraded .... forgot to wait/forgot to backup ... same thing happened at the beginning of Sierra ... seems to be an Nvidia issue ... and can’t shut that card off.
Just wondering... did you install any gpu driver from NVIDIA or are you just using the ones that came with the OS?
Also: did you try in Safe Mode? Any difference?
And yet: you could try when started normally and logged in to a different user account. Any difference?
Hi Luis:
I used the NVidia drivers from the web. When I started in safe mode, I could mirror the displays. When I rebooted in normal mode, the screens where mirrored. I could turn off the mirroring, but when I tried to re-mirror it, it wouldn't do it ... don't have time to try the other user login at this time.
Hi Luis:
Nvidia allows you to choose which driver to use: OS or Nvidia. Requires a reboot. Did that (switched to OS drivers) ... still had the issue ... Then I tried starting in safe mode. After restarting in safe mode, the monitor was mirrored, and then, after rebooting into normal mode, the monitor was still mirrored; I switched back to extended screens then, and was not able to switch back ...
Couple of stills showing a split second with both displays mirrored, and then extended ...
Likely because in mirrored mode the screen resolution is also mirrored. Your external display probably can't display the screen resolution of your computer.
Try resetting NVRAM and SMC.
Luis ... thanks, but that didn't do anything ...
This seems to confirm it is a driver issue.
If you just use the drivers supplied with the OS, you should have no problem.
Since upgrading to High Sierra, I can't mirror an external monitor. 15" Late 2013 MBP with Nvidia 750 GPU; worked before upgrading. Is there a newer driver available?
