External monitor problem iMac 2017 High Sierra.

I had to buy a new KVM after updating to El Capitan to get 1920 x 1080 because VGA no longer worked. When I updated to Sierra, I had to buy two different KVMs, an Aten and a Lynksys. The Linksys was stable, but I just updated to High Sierra on my 2012 Mac Mini and cannot get the resolution. I just bought a connect pro and several HDMI EDID ghost adaptors and none of them solve the problem. I tried them in front of the KVM and behind the KVM in front of the Mac. I cannot afford to update my 2014 Mac Mini because I cannot do my job and personal work without it.

I love these Mac Minis but I just don't understand why I need to buy new hardware every year to use the same Apple devices. Much as I love these Mac Minis I probably need to make do with them through their life and then u ultimately replace with iMacs.

The monitor only really runs in one ideal resolution. 1080p I think that it is called.... 1900 x something I forget. The Mac sensed it automatically in Sierra. In High Sierra I have to change the orientation to sideways, which forces it to detect the resolution, and then I allow it to revert and it is great. If I’m in a hurry I’ve become pretty adept at using a mouse on a sideways screen to rotate it back. I have tried picking scaled and saving it but it always goes back to default, which doesn’t work since High Sierra. I first learned these techniques when VGA broke in El Capitan.

No. I may revert it back to Sierra but that will require 60 to 80 hours to get it all configured and everything installed again. I also might play with it as a headless Mac Mini if I can convince it to come up in a reasonable resolution with an EDID plug. The advantage there is that I can test it with each minor High Sierra update. I don‘t see myself ever buying another Apple device which does not come with an integrated screen. Although the Mac Mini is a perfect device for KVM use I can’t go through this every year.

Today I have updated to macOS 10.13.2 and my curved Samsung external monitor is back to work!!! Thanks Apple.

But...

When I login to my MBP2017 from lock screen... I have a blue screen coming every 3 secs.

So half way, just half way to fix this external monitor issues completely.

FYI: when I plug the Satechi 4K hdmi dock from the type-C port and I plug it back in, the monitor works again.

Waiting for the MacOS High Sierra 10.13.3 update coming soon.

Hi Eddiemacias,

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

I bought a new MacBook Pro yesterday. My apple Thunderbolt Display works going from my computer's USB-C port through an apple adapter into the Thunderbolt Display. My Samsung
TV does not work going from my computer's USB-C port through an apple adapter through a Thunderbolt(original)/ HDMI cable into the TV. I upgraded my DisplayLink software, but that didn't solve the problem, although somewhere in the process it implied that the DisplayLink software was USB related, not Thunderbolt related.

Well just got the latest High Sierra... Mac mini still does not automatically sense or retain resolution with HDMI . Still need to do the 90 degree rotation and revert procedure to get it to detect it. If I don’t I cannot see the top menus or the bottom dock, pretty much making my Mini unusable.

When connecting Satechi or similar USB-C -> HDMI adapter most of the time Mac will completely freeze (15 inch MacBook Pro mid-2017).

After testing bit of testing, problem seems to be solved using any USB-C -> Displayport/mDVI/DVI cable or adapter. I used new DELL U-series monitor.

Apple, we are waiting for a fix!

Ok, I made the stupid mistake of allowing my newer Mac Mini to get minor updates... security updates to Sierra. It no longer detects my monitor . I am going to buy a Dell as I need a working machine

i have a very similar problem. my external HP ZR2440w with an hdmi to hdmi cable works fine - even after the update to high sierra. however, i have a separate external monitor, an HP Z24i, with an hdmi to display port connector that i use at a different location where i travel. the mac cannot detect that monitor.

does this mean that high sierra can't support an hdmi to dispay port cable?

I had a similar problem but eventually bought a USB-C to displayport adaptor and connect the secondary monitor via a displayport lead. This is the only thing that worked for me having purchased and returned many different types of leads and adaptors even apple branded ones. This is the only one that I found that actually worked- KiWiBiRD® USB 3.1 Type C THUNDERBOLT 3 to DisplayPort 4K Adapter (DP v1.2a, UHD 4Kx2K 3840x2160, 15.6cm Lead, USB-C to F…

Everything else was unstabled or didn't work at all.

i have the usb c to hdmi/usb 3 output dongle made by apple and plug the hdmi end of the connector on to that -which works great for the monitor that has the hdmi connection, but my monitor at my other house only has the display port. i'd hate to think i'd have to use an adapter that doesn't allow for the power supply to be plugged in at the same time - plus i need the usb to connect the data cable as i use the usb ports on the monitor to run my back up drive, optical drive and external keyboard with its own usb's. i also have no problem using the hdmi to hdmi for my TV connection on the rare occasions i want to hook my laptop up to it. this is a macbook 12", not the pro that has two usb c connections

I tried USB-C -> Displayport and it doesn't work for me :-( (I have a Dell U2717D)

I am starting to be desperate about this. Thinking about selling my monitor and buying a new one. I don't understand how Apple can do this...

Guys! I found the solution!

I have a iMac late 2013 and I have two external monitor. 1 24 pouces (1200 x 1920) and 1 25 pouces (2560 x 1440). I disconnected the 24 pouces (1200 x 1920), allowed the "monitoring copy" (don't know how to say it English, it's when both screen show the same screen) and so I was able to change the resolution to 2560 x 1440. Then I disabled it and here we go! 🙂

Everything works fine for me right now.

I feel for you but Cnet has highlighted a potential problem with this monitor when connecting to USB-C

Dell UltraSharp 27 (U2717D) review - CNET Not fair that Apple effectively makes people's hardware obsolete in this way though.