Strange split column behavior with external display

Question

Strange split column behavior with external display

My old 30" NEC display is working fine with my 2012 MacMini via MiniDisplayPort adapter to DVI, at 2560x1600.

I got a new M3 MBP, and it shows a strange issue, using two different brand USBC-to-DVI adapters, the MBP output is split in three columns, the center one is correct, but the lateral ones are swapped, meaning the left part of the screen is to the right and viceversa (see attached pic).

I spoke to the Apple support but the person at the phone had no idea and told me to visit the Genius bar.

Any idea what is happening here? I tried two different adapter brands because one may not have been compatible, but the second one displays the same behavior. And the fact that the NEC display works with the same cable and the MacMini with Catalina demonstrates it's not a display/cable issue.

Monitor driver in Sonoma? What else? Messing with the OSD of the NEC didn't help. I wouldn't like to cash out another 1k+ for a new display, since this is still working pretty fine after 15 years.

MacBook Pro 15″, macOS 12.0

Posted on Dec 22, 2023 8:57 AM

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Answer 1

Top-ranking reply

Grant Bennet-Alder

Level 10

143,915 points

Dec 22, 2023 1:15 PM in response to madsalmard206

Oh, I see what the problem is. You are using DVI

DVI Displays up to 1920 wide (and NOT wider!) can use ordinary, single-link DVI, with three color signals. if you reduce your resolution as a test to 1920 wide, all should go back to normal.

DVI 'runs out of gas' above 1920 wide, and the fix was to add an additional set of three color signals. This is called Dual-Link DVI. it requires adapters that support Dual-Link DVI , and your cables must have all conductors connected end-to end. it cannot work above 1920 wide with these pins missing, but they may be present but not connected.

the extra signals are medium blue in the center of the connector.

drag and drop on preview to see larger

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Answer 2

Dec 24, 2023 1:07 AM in response to Grant Bennet-Alder

Hey Grant,

thanks for your support, I solved it anyway and get full fine resolution image at 2560x1600 with my 30" display now without column-swapping issue.

I tried and tested many different combo of USB-C to DVI adapters / cables but none worked, until yesterday I tried a different route that finally worked:

I had to use the USB-C to Mini DisplayPort adapter and a Apple Mini DisplayPort to DVI adapter (the active one, with USB-A port and cable) in serie. Then connect the Apple adapter and the display with a DVI-D Dual-Link cable.

Note for other people that may stumble in the same behavior that for the Apple adapter to work the USB-A split-end cable needs to be inserted into a powered USB-A port. It has a passthrough port though, so you regain the lost port anyway.

I now see also others are affected with the same: https://discussions.apple.com/thread/255295938?answerId=259983248022&sortBy=best#259983248022

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Answer 3

Dec 22, 2023 12:47 PM in response to madsalmard206

is the display resolution the display uses the same as the maximum resolution the Mac is sending?

 menu > about this Mac > (system Report) > Graphics & Displays

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Answer 4

Dec 22, 2023 10:12 AM in response to madsalmard206

check the internal settings "on-screen display" -- settings in the display itself, not on the Mac.

that picture has the look of Picture-in-Picture gone crazy.

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Answer 5

Dec 22, 2023 12:52 PM in response to Grant Bennet-Alder

yes, tried also different resolutions but this Pacman-tunnel effect remains. Does anyone know if with an utility like BetterDisplay I would be able to shift / adjust all the picture horizontally to the left? For now I resorted using Screen Sharing from my old MacMini but I'd really like to use the MBP with the display natively or at least without involving the network.

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Answer 6

Dec 22, 2023 12:03 PM in response to Grant Bennet-Alder

Unfortunately no PiP mode for this display is available. I tried messing around with the OSD settings like moving picture left but it is limited and stops after a few pixels.

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Strange split column behavior with external display

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