Connect 23" Apple Cinema Display with Thunderbolt 3 iMac (2020)

Question

Level 1

13 points

Connect 23" Apple Cinema Display with Thunderbolt 3 iMac (2020)

I have an Apple Cinema Display 23-Inch (Aluminum) that I’m trying to use as a secondary / external screen on my wife’s iMac 2020 (Catalina).

I purchased a USB Type C to DVI Female adapter that arrived today and connected it to the DVI cable that comes with the “brick” power supply into the thunderbolt port at the back of the iMac.

The LED power light is on the Cinema Display and the USB cable from the “brick”power supply is connected to the iMac.

The good news is that the Arrangement tab now appears within System Preferences / Display but the Cinema Display screen is black. I’ve included a couple of pictures.

I’ve gone back online and taken suggestions including rebooting the machine - more than once., rebooted into Safe Mode to ensure each screen is set to its default display settings. I’ve gathered displays and held down the option key to detect displays. The Mirror Screen box is not ticked (ok maybe I am). I’ve logged out and put the iMac into Sleep Mode but no joy.

There’s nothing wrong with the Cinema Display. I can still plug it back into my wife’s old 2.12 iMac and it’s all systems go.

Thoughts?

iMac 27″, macOS 10.14

Posted on Dec 2, 2020 11:47 AM

Reply

Answer 1

Mar 29, 2021 2:23 PM in response to m.schaber

HI m.schaber.

Yes I have the same model as you have with RTD2171U Chispet and on the left of the bar code is the number 61213. Thescreen shows up on Apple Cinema Display 23 but with wrong refresh rate is definitely lower than 60hz and resolution on the ACD23 on this delock is 1920x1080 and the Apple Cinema Display have problem with force the right resolution. I have made in photoshop the issue :) becuase I don't want to plug again this screen to show it :) and reproduce how it works.

So this looks like it force 1920x1080 but for rest of the pixels on the bottom 120px it copy the top of the screen to fill it :)it is really strange.

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Answer 2

8989a

Level 1

19 points

Jan 29, 2021 11:06 AM in response to blueroofnet

I was wondering if it is possible to convert the HDCP ON model to HDCP off as the ON model is easy to find.

The update is possible to disable the HDCP on the adapter with a Windows Based system.

Best regards

Club3D Support

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Answer 3

Feb 20, 2021 9:51 AM in response to blueroofnet

I have the exact same problem. The adaptor mentioned seems to be for a 30" Cinema Display and resolutions 3840x2160@30hz, 2560x1600@60Hz. Mine is a 23" with a resolution of 1920x1200. can anybody confirm this adaptor is the correct one for solving this conundrum? Just want to make sure before I spring for $43.00 Thanks, David

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Answer 4

8989a

Level 1

19 points

Feb 20, 2021 12:09 PM in response to davidramsey

I use them for 23" cinema Monitors, it works. However when running external monitors on 27" iMac Big Sur the computer randomly crashes, however it also crashes with modern Lenovo monitors using USB-C to DPI leads. I think its a problem with Big Sur rather than the monitors.

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Answer 5

Feb 23, 2021 7:31 AM in response to blueroofnet

For me this one worked:

• DeLock 61213 (USB-C to DVI-female) Adapter with the following Chipset: Realtek RTD2171U

(It was an Apple Cinema Display 23" (1920x1200) with the brick power supply and the special "branch-cable" or cable whip: special power connector, USB2.0, FW-400 and DVI-male).

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Answer 6

blueroofnet Author

Level 1

13 points

Feb 23, 2021 7:58 AM in response to davidramsey

I'm sticking with Catalina for now until BS gets its kinks worked out. Not worth the extra "fire power" and time to move on. Also worth mentioning that I used this adapter https://astropad.com/product/lunadisplay/ to get an 2010 23" iMac working as a secondary screen on my wife's Catalina 2020 iMac.

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Answer 7

Mar 24, 2021 11:42 AM in response to m.schaber

I have bought this dongle od Delock DeLock 61213 (USB-C to DVI-female) Adapter with the following Chipset: Realtek RTD2171U and it is only support 1920 x 1080 :/ Apple Cinema Display is 1920 x 1200 ... it is possible to force it this resolution on mac ?

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Answer 8

Mar 29, 2021 2:08 PM in response to ThomasMomeu

Hello ThomasMomeu.

You are right. The adapter says 1920 x 1080 only, but I use the Delock DeLock 61213 adapter successful with an EIZO Screen with 1920 x 1200 (which had the same problems as the Apple Cinema Display 23" – flashing on/off). So I am quite sure that in my setup the Apple Cinema Display would work as well (I did one test before I posted the solution, but I can't tell you in the long run …).

On the product page of the adapter it even says (technical detail page):

https://www.delock.com/produkte/G_61213/merkmale.html

website: delock.com > produkte > G_61213 > merkmale.html

Maximum screen resolution

• 2560 x 1600 @ 60 Hz

• 3840 x 2160 @ 30 Hz

• 4096 x 2160 @ 24 Hz

So it should work with 1920 x 1200 @ 60 Hz.

You can try to install the Switch Res X system extension as well, but I did some tests and in my case it did not help to solve the chipset issue.

https://www.madrau.com/srx_download/download.html

madrau.com > srx_download > download.html (srx = Switch Res X)

Best m.