Trying to connect 2017 Macbook Pro to The Apple Cinema HD 30-inch display not working

Updated on 26-05-2021 in Adapters and Cables
4 on 04-05-2021

Hello – I bought the CAC1510-a-HDCP Off  in the hopes that I could connect my 2017 Macbook Pro to my old Apple Cinema HD 30 inch display.  However when I connect everything and go to my display settings, hold down the control key and click on the Scaled radio button – I only have two options – 1280×800 and 1024×640.  I’m including all of the pics of my product and what I’m seeing on my screen – I’m really hoping someone can assist with this as everything on your website said this would work.  Is there some other settings I should be changing that I’m missing?


Sherry Ott – [email protected]

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0 on 04-05-2021

Hello Sherry,

You need to hold the Options key, not control :).

Option + “Click” Scaled

Hope this helps.

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2 on 05-05-2021

Is the CAC-1510-A connected directly to the MacBook Pro? Holding the Option key and clicking “Scaled” should show all the modes including 2560×1600.

The CAC-1510-A cannot do 2560×1600 if it’s connected to a USB-C dock that supports USB 3.x but it should be fine when connected to a Thunderbolt dock. The reason is that it is limited to HBR link rate which requires 4 lanes to do 2560×1600 and USB-C docks that support USB 3.x only support two lanes.

The AGDCDiagnose command in macOS tells you the DisplayPort connection type (link rate and link width). The CAC-1510 should be [DP 1.2 4 x HBR ]


on 24-05-2021

I am connecting this directly to my MacBook, not through a  USBc dock.

When using the option key, I see the following:

on 26-05-2021

What version of macOS?

Does SwitchResX show the 2560×1600 timing?

Post the result of the AGDCDiagnose command to or something.

/System/Library/Extensions/AppleGraphicsControl.kext/Contents/MacOS/AGDCDiagnose -a > AGDCDiagnose_a.txt 2>&1
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