2018 Mac Mini with DVI monitor issues...

Loddonlily

macrumors newbie
Original poster
Nov 20, 2018
9
3
UK
Hi - newbie here, taking my first steps in the world of MacOs with a new Mac Mini. Have been reading with some anxiety about the various monitor issues that people have been having and am concerned that it might not be fit for purpose... which would be odd, as I don't think my requirements are demanding.

I have an i3 Mac Mini with 8GB/256GB. I want to connect it to a 24" 1920x1200 monitor with HDMI - this is working fine. But I also want to connect it to a second monitor, 1280x1024, with DVI, and this is not working for me. I've now tried two different USB-C to DVI-D cables - one of them specifically claiming compatibility with the 2018 Mini. Neither work with the DVI connection to the smaller monitor, though they do work with the DVI port on the 24". Sadly the smaller monitor doesn't have an HDMI port so I can't just swap. And, yes, I can use the DVI on the smaller monitor on another machine (Windows) where it works fine.

When I say "not working" - it's ok at the login screen stage but as soon as the boot process progresses to where it sets the resolution accurately, I get crazy flashing on the screen. The image is there, the size I expect, but flashing multiple times a second.

Anyone have any suggestions, or do I need to return this?
 

Loddonlily

macrumors newbie
Original poster
Nov 20, 2018
9
3
UK
Update in case anyone is following this... I've spent some time today on to Apple support (chat and phone). The official answer is (1) the machine supports 1280x1024 (2) they don't think mine is broken and (3) after that I'm on my own. Alleged problem/deficiency with monitor and/or cable. Bear in mind that monitor works fine with a windows PC and I've tried two different cables. Suggests hidden compatibility issues.

Lesson: make no assumptions about what is or is not going to work with this thing...
 

tthkbw

macrumors newbie
Jan 13, 2009
19
16
Portland, OR
Update in case anyone is following this... I've spent some time today on to Apple support (chat and phone). The official answer is (1) the machine supports 1280x1024 (2) they don't think mine is broken and (3) after that I'm on my own. Alleged problem/deficiency with monitor and/or cable. Bear in mind that monitor works fine with a windows PC and I've tried two different cables. Suggests hidden compatibility issues.

Lesson: make no assumptions about what is or is not going to work with this thing...

Does the display section of preferences on the Mac allow any other resolutions? Try others, if so. Also, select "About this Mac" from the Apple menu, then "system report". Then select "Graphics/Displays". What does it say about your monitors there? Do refresh rate and resolution for the non-working monitor match its Specs?

I notice that monitor has a VGA input as well. Have you tried that using an adapter?

Regarding assumptions, you are absolutely right, particularly with respect to Macs. I also have a Mac mini, and am using a Dell P2415Q monitor connected via HDMI. When I contacted Dell about an issue, they informed me they did no testing with Macs and I needed to connect the monitor to a PC to verify it worked!
 

Loddonlily

macrumors newbie
Original poster
Nov 20, 2018
9
3
UK
Hi - yes, the display preferences did show some other (lower) resolutions and I did try these, as well as the non-preferred but available resolutions accessed by pressing (IIRC) Options. As expected - got a lower resolution display, but still mad flashing.
I don't have a suitable MacMini to VGA adapter and don't want to waste money buying one because I need the VGA input on that monitor for something else (a Linux box!).
In the end I think the cleanest solution is to buy a new monitor that has HDMI input, then I can use the cables I have and operate everything in a space it's comfortable with...
 

djc6

macrumors 6502a
Aug 11, 2007
571
124
Cleveland, OH
In the end I think the cleanest solution is to buy a new monitor that has HDMI input, then I can use the cables I have and operate everything in a space it's comfortable with...
You could go down the rabbit hole of EDID overrides:

https://michaelcivitillo.com/overriding-edid-on-osx-for-external-monitors/

https://en.wikipedia.org/wiki/Extended_Display_Identification_Data

EDID is how monitor describes its capabilities to the computer - if there is an incompatibility, its probably in how macos is interpreting the EDID information and overriding it has a decent chance of fixing.
 

Loddonlily

macrumors newbie
Original poster
Nov 20, 2018
9
3
UK
Hmm, that's a dive I think I'd rather not take! As it happens, in my case the OS was able to fetch the monitor model number and natural resolution correctly - though that doesn't mean that other information wasn't misfetched.

In the end I have to put a value on my time and, however I reckon it, I've already "spent" more than the cost of a new basic monitor!
 
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dmw5000

macrumors newbie
Feb 8, 2019
1
0
Hmm, that's a dive I think I'd rather not take! As it happens, in my case the OS was able to fetch the monitor model number and natural resolution correctly - though that doesn't mean that other information wasn't misfetched.

In the end I have to put a value on my time and, however I reckon it, I've already "spent" more than the cost of a new basic monitor!
Did you ever manage to resolve this? I just bought a Mac Mini and my Eizo DVI monitor flashes and my NEC dhows the desktop for a millisecond and then goes black. Works fine with the second cheap monitor that connects by HDMI. My DVI to USBC cable works fine with a new Mac laptop with the same OS and video card. I have 6 DVI monitors so don't want to throw them all out and buy new HDMI monitors as I replace my older macs with newer ones.
 

Loddonlily

macrumors newbie
Original poster
Nov 20, 2018
9
3
UK
Only by getting my credit card out! I had to dump the Eizo monitor, and bought a new Dell one instead which I now connect with HDMI. Just to be clear, though, it's not all DVI monitors - my large HP monitor (which I'm using right now!) is connected by a USBC-DVI cable.