Level 1

36 points

External monitor problem iMac 2017 High Sierra.

I try to connect a Samsung external monitor to my new 2017 iMac, but the monitor isn´t being recognized. I used the same monitor with my 2012 Mac mini and it all worked fine (even with two monitors).

I use a new USB – C 3.1 to DVI adaptor, but my iMac isn´t recognizing my Samsung monitor.

I have just updated to Mac OS High Sierra and it still doesn´t work (it didn`t work with Mac OS Sierra either).

And yes, I have opened up system preferences and Displays. Using my Mac mini, the Samsung display showed up in preferences.

Searching the net, it seem to be a problem for many people, but I cannot find a solution.

Any suggestions?

Thank you.

Jesper

iMac, macOS High Sierra (10.13), null

Posted on Sep 26, 2017 6:28 AM

Top-ranking reply

d3vinda

Level 1

9 points

Posted on Nov 20, 2017 5:31 PM

Hi RashDK,

You should be able to resolve the issue by just updating your DisplayLink driver. All external video adaptors (usb2hdmi/usb2vga/etc..) share the same driver.

They have an updated driver for High Sierra which fixed the same issue I had as the others in this thread.

Display Link Driver: http://www.displaylink.com/downloads/macos

Hope this helps. 🙂

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235 replies

hvdk

Level 1

9 points

Oct 4, 2017 1:07 AM in response to RaskDK

Hi. I have the same issue with an external monitor. It worked fine (Sierra) before I installed High Sierra (Macbook Pro - Dell P2011H)

Oct 19, 2017 11:46 AM in response to RaskDK

I have downgraded to Sierra via a timemachine backup and it has fixed the problem and would presume this would also be the case with any other earlier OSX.

Nov 9, 2017 10:15 AM in response to csdoyle

Thank you csdoyle! Installing the new displaylink driver worked for MBP connected to Dell u3415w via Anker adapter and StarTech doc. Apple, I'd like the last two hrs of my life back, plz.

RaskDK Author

Level 1

36 points

Sep 26, 2017 11:18 AM in response to den.thed

Thank you for replying.

Unfortunately, it didn´t work. Still not recognizing my external monitor.

Next up I will get the adapter exchanged.

Wired that Apple hasn´t fixed the problem yet. It seems to be a problem that many people experienced when upgrading to OS X Sierra.

RaskDK Author

Level 1

36 points

Sep 29, 2017 6:17 AM in response to den.thed

So, I tried a new adapter, and it didn´t work either. What can I do? Downgrade to an older OS version or buy a new monitor?

Any suggestions as to which monitor to buy? I guess it will have to be a thunderbolt 3 monitor (which I presume I can connect directly to my iMac 21.5 2017?).

Thank you

Oct 8, 2017 2:39 AM in response to RSU14TeacherTech

The fact that Apple say it is not supported is neither here nor there, the fact is we were all able to do this and now the ability has been taken away. In my case I was not using the dual monitors direct but through a thunderbolt dock with a USB adapter for one of the displays and it worked rock-solid until this update.

I also have plenty of other issues including an HP printer that the MacBook Air now thinks is an unreadable external disk.

I would love Apple to be able to just issue me with a copy of Sierra that I can reinstall..............

Oct 8, 2017 8:41 AM in response to RaskDK

I have same issue with a macpro (desktop) and sony monitor. I need to unplug monitor and replug to get the computer to work, and oddly computer seems to go to sleep after a while. BOth display and computer are set to stay on. Even turning off the tv and turning back on doesnt help; actually have to unplug and let it reboot

Oct 9, 2017 5:49 PM in response to RaskDK

I am also experiencing issues after upgrading to High Sierra.

I had 2 external monitors running at 4k and I am experiencing two issues.

1. One monitor outputs a blue screen. Sometimes a unplug/plug in helps sometimes not.

2. My external sound card drops the sound randomly when the monitors are plugged in.

Seems there is something with this that Apple broke that was working in Sierra.

Will update if I find any changes.

Matthew

Oct 9, 2017 7:22 PM in response to RaskDK

Same issue here, wish I had never done the upgrade to High Sierra! I really need the second screen and now it isn't available!!I have a 2016 MacBook Pro and a late 2013 IMac same problem with both.... Please fix ASAP Apple, I am a dedicated Apple user for all platforms of technology sooner than later would be best!

Oct 10, 2017 5:12 PM in response to RaskDK

I am having the same issue. I just updated my iMac to OSX High Sierra and my second display stopped working. I can move the mouse to it but no content is shown. It was working fine under sierra. Very annoying, breaks up my workflow. 😟

SimonLMG

Level 1

8 points

Oct 10, 2017 6:41 PM in response to RaskDK

Can report the same here from London. Upgrade to High Sierra yesterday and now only one of the two external monitors works. I have a small professional home studio so it feels as though someone's pinched my mixing desk!

pixerati

Level 1

4 points

Oct 11, 2017 9:23 AM in response to RaskDK

My late 2012 MacBook Pro won't boot if the Apple Thunderbolt display is plugged in (I have to plug it in once the laptop's booted. Then once working with it I have all kinds of graphics issues–frequent corruptions, inability to display some video. The laptop on its own is working fine (well, fine-ish–I still get a bunch of permanent freezes that I never had pre High Sierra).

Oct 17, 2017 12:42 AM in response to oddgoingson

No, I didn't have a working Time Machine backup from just before the upgrade (something went wrong with the hard drive I was using), so had to follow instructions on how to rollback and reinstall from a backup made after the upgrade, but the rollback instructions left me with no working OS so I had to do a full fresh install of High Sierra from an erased internal hard drive.

Teach me to forget to test the backup.......

Oct 18, 2017 7:28 AM in response to RaskDK

Hi all,

I have installed the Beta and want to report that I not experiencing any issues yet. I will be testing further and reporting any issues I find to Apple.

Hopefully this update will address the issues you are having.

Matthew

RaskDK Author

Level 1

36 points

Oct 19, 2017 5:45 AM in response to RaskDK

So, I tried to install Mac OS High Sierra version 10.13.1 beta (17B35a), but it still isn`t working. My iMac 2017 isn`t recognizing my external Samsung monitor (DVI to Thunderbolt adapter).

I have tried everything except downgrading to EL Capitan. With an all new iMac will downgrading work? Anyone who actually done the downgrade? Was the external monitor recognized?

I need my external monitor, so one final question. Can I use all USB-C monitors?

Thank you

Jesper

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External monitor problem iMac 2017 High Sierra.