2019 iMac, connecting Second display different from previous models?

dangoland

macrumors member
Original poster
Jun 14, 2008
82
23
I recently got a 2019 27" iMac and it doesn't seem to be connecting to other displays even though the adapters have worked with other configurations. Did something drastically change between earlier models and this one? Here is some background:

• I have a Dell 3007WFPt monitor that worked great with my previous imac. It only accept dual link DVI, and worked great with Apples MiniDisplay port to dual-Link DVI adapter at full resolution 2560x1600
• I got this USB-C to HighRes Mini display adapter that supposedly accepts such a thing and reviews mention it working: https://www.amazon.com/gp/product/B017TZTMBG/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

It does not work at all with the 2019 iMac, even when connecting the dual link adapter, a regular mini display adapter to regular DVI, a Mini display port to HDMI connected to a different HDMI monitor.

The adapter from Amazon however will work on a 2018 Mac Mini using MiniDisplayPort>HDMI and as far as MiniDisplayPort>HDMI>DVI

Originally I thought the adapter just wasn't working and even got a replacement, but they work with earlier macs, just not this one. Any idea what I can do to get this brand new 2019 27" iMac to connect to a dual link DVI display, or perhaps any other display altogether? What exactly should I be looking for?

Been trying to figure this out for days and I'm at a loss.
 

priitv8

macrumors 68040
Jan 13, 2011
3,517
437
Estonia
This seems to be a USB-C type 3.1 cable on the computer end. MiniDP on the other end.
I have not heard, that Mac-s would output video from USB, especially without a driver, as the product description suggests.
You'd need adapter that has miniDP or Thunderbolt at the computer end.
Buyers' comments lower on that page reinforce that impression.
That's the bad news with USB-C connector - it can house 3 fundamentally different interfaces: USB, DisplayPort and ThunderBolt.
 

mikehalloran

macrumors 68000
Oct 14, 2018
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The Sillie Con Valley

HuskerHarley

macrumors regular
Oct 28, 2017
244
164
Lincoln
Glad I stumbled onto this thread. My iMac (1st Time Owner) is scheduled for delivery today. I plan to use my hp monitor as a second display...Guess I need to head to BB and get an adapter. Thanks for the great info.
 

mikehalloran

macrumors 68000
Oct 14, 2018
1,600
390
The Sillie Con Valley
Good to know! And I stand corrected.
This does not mean that you can connect every monitor ever made, of course. What and how does depend on the GPU.

You can, however, connect something to any Mac with the USB-C port. The entry MacBook, for example does not support Thunderbolt at all.

Apple techs are pretty knowledgeable on this so, if you have something unusual, give them a call.

It would surprise me if it was possible to connect the old 23" Cinema Display with the plastic bezel — even if you have the special adapter box... but they will know.
 

dangoland

macrumors member
Original poster
Jun 14, 2008
82
23
THank you for the answers, the main pronlem that I'm having is that using this adapter I havent been able to use ANY external monitors. https://www.amazon.com/gp/product/B017TZTMBG/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

Usint this adapter Have tried it as Mini Diplay port to DUal Link DVI, Regular DVI, Mini Display port to HDMI. The 2019 iMac recognizes none of these with this adapter. Works with other Macs, including 2018 Mac Minis. I'm at a loss.