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User profile for user: tltaylor01
tltaylor01 Author
User level: Level 1
9 points

I have a 2009 IMAC. I am trying to use it as a dual monitor with my new 2019 IMAC. I purchased the proper cords, thunderbolt three to two adapter. I connected the video port to the proper adapter. Following the above command 2 and cmd fn 2

Can anyone help me diagnose my problem? I have a 2009 (late) Imac running high Sierra 10.13.6. I have tried all the suggestions to use it as a dual monitor with my 2019 IMAC. Nothing has worked. I have tried all the troubleshooting suggestions with no results. There's no indication that the two computers are connected. Can anyone suggest other options?


iMac 21.5″, macOS 11.5

Posted on Aug 16, 2021 7:48 AM

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User profile for user: Limnos
Limnos
User level: Level 10
418,903 points

Posted on Aug 16, 2021 7:50 AM

Use your iMac as a display with Target Display Mode - Apple Support - https://support.apple.com/HT204592 -. HOWEVER, this document is "archived" which means this feature is no longer supported on the new line of Macs and operating system versions that are currently supported by Apple. The document applies only if all system versions to be used date from 2019 or earlier and the display models used are iMacs late 2009-Mid 2014


This could only be done with a very few and very specific older iMacs and support was very limited. Read this topic for a 2021 perspective on this: https://discussions.apple.com/thread/252271436?answerId=254300142022#254300142022

and this 2021 post by Allan Jones about software limitations:

https://discussions.apple.com/thread/252344497?answerId=254428494022#254428494022



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User profile for user: Limnos
Limnos
User level: Level 10
418,903 points

Aug 16, 2021 7:50 AM in response to tltaylor01

Use your iMac as a display with Target Display Mode - Apple Support - https://support.apple.com/HT204592 -. HOWEVER, this document is "archived" which means this feature is no longer supported on the new line of Macs and operating system versions that are currently supported by Apple. The document applies only if all system versions to be used date from 2019 or earlier and the display models used are iMacs late 2009-Mid 2014


This could only be done with a very few and very specific older iMacs and support was very limited. Read this topic for a 2021 perspective on this: https://discussions.apple.com/thread/252271436?answerId=254300142022#254300142022

and this 2021 post by Allan Jones about software limitations:

https://discussions.apple.com/thread/252344497?answerId=254428494022#254428494022



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I have a 2009 IMAC. I am trying to use it as a dual monitor with my new 2019 IMAC. I purchased the proper cords, thunderbolt three to two adapter. I connected the video port to the proper adapter. Following the above command 2 and cmd fn 2

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