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agpastore Author

Level 1

40 points

MacOS Sierra not recognizing external displays and going black

Hi.

I've just upgraded to macOS Sierra on my MacBook Pro Retina Mid 2012.

After the upgrade, my Mac is not recognizing any external display:

I've tried HDMI and DisplayPort to VGA adapters.

The Retina monitor "blinks" but not signal is detected on external displays.

Also, after rebooting, also the retina monitor goes completely black (the mac has booted, because I can trigger Siri commands!).

To restore the situation I need to put the mac to sleep, plug in an hdmi monitor (which does nothing), wake up the mac and eject the plug. After this sequence the retina monitor goes back on (and only that!).

I've tried to reset NVRAM and SMC: no effect.

I've tried to boot into safe mode or recovery mode, but the retina monitor remains black, as well as any other external display (the same happens if I try too boot with or without a connected external display).

I'm stuck and have no idea on what to do. I cannot even try to reinstall the OS, as no video works just after reboot.

Any hint would be appreciated.

Thanks!

MacBook Pro (Retina, Mid 2012), macOS Sierra (10.12)

Posted on Sep 26, 2016 4:31 AM

Best reply

TmacKilla

Level 1

4 points

Posted on Apr 19, 2017 7:56 PM

I checked the Nvidia website for mac drivers for sierra. LOW AND BEHOLD! THEY EXIST!

http://www.nvidia.com/object/macosx-cuda-8.0.46-driver.html

This little driver made my 2012 Mac Pro Retina with 660 GTX actually fly and run way more efficient graphic wise and fixed my external monitor hiccups.

you can update via system prefs.

Didn't feel the need to search for drivers until I installed MAC OS SIERRA.

EVEN THOUGH I LOVE APPLE! GREAT PRODUCTS! SHAME ON APPLE FOR GIMPING THE GRAPHICS DRIVER IN AN ATTEMPT TO FORCE UPGRADE!!

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109 replies

Nov 17, 2016 6:45 AM in response to Jack Weinbender

Restarted, back to nothing.

Nov 17, 2016 9:49 AM in response to agpastore

Same thing. Sometimes its OK, most of it, not OK.

Just got back to El Capitan. So far, 100% working.

The problem for sure is Sierra.

Dec 3, 2016 3:42 PM in response to agpastore

Had a problem with my VGA to USB display after installing Sierra. Didn't recognize it at all.

Solved it by installing the latest DisplayLink driver (3.0 Beta 1) -> http://www.displaylink.com/downloads/osx

Dec 4, 2016 12:08 PM in response to agpastore

It is because Apple doesn't support older monitors anymore. I have a HANNS-G HW191D monitor connected to a Thunderbolt docking station and in El Capitan this setup worked perfectly but after "upgrading" to Sierra the Monitor is not recognised at all. First I thought the docking station or cable was not working but when I rebooted the macbook pro into bootcamp the monitor worked again without any problems.

So then I thought maybe Sierra doesn't support dual monitor on my setup anymore but I could connect my LG TV with the same DP+HDMI cable and the TV was immediately recognised.

This is definitely a change in the new MacOS update that causes older external monitors to break. Shame on Apple.