Target Display Mode not working 2020 MacBook Pro (Catalina)

Hello, what cables/adapters are you using for this connection:

"I have a 2010 27" iMac and it is working fine in target display mode with my new 2020 MacBook Pro 13". "

All Apple cables. Doesn’t matter anymore, I threw into the ocean.

Can you please write out the name of the youtube guy and name of the video? The link was removed by Apple and I would love to check this out as I still can't find a solution!

run 6 displays m1 ruslan tulupov

The thread is all about connecting old Macs as secondary display for new Macs - not for data transfer.

I agree-what a misleading product.

the following screenshot shows my setup's technical details:

(compression artifacts due to apple's forum software, hi res available upon request if needed)

This is very frustrating, I just purchased a 2020 MBP and like everyone on here has stated, TDM no longer is compatible with the 2020 models. I’ve submitted feedback to apple but I’m Sure they won’t respond and they will not provide an update/resolution to the current OS. It’s comical that apple removed this feature, I guess it’s all about buying new products and getting new business vs keeping current apple owners happy. Now I have a 2011 iMac that can’t get updates and now I can’t use it as a monitor.

No. The newest iMac supported is an "old" 2014 model.

iMac models from 2015 or later will not work, EVER

and 2020 MacBook Pro and newer models will not work, EVER

You can connect any of these older iMac models to another Mac from 2019 or earlier for use as an external display. Learn how to identify your iMac model.

• • • 27-inch iMac models introduced in 2009 and 2010: Use a Mini DisplayPort cable to connect your iMac to a Mini DisplayPort or Thunderbolt or Thunderbolt 2 port on the other Mac.
    • All iMac models introduced in 2011, 2012, 2013, and mid 2014: Use a Thunderbolt cable to connect your iMac to a Thunderbolt or Thunderbolt 2 port on the other Mac. If the other Mac uses Thunderbolt 3, you can use the Apple Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter with your cable.

Target display mode requires macOS High Sierra or earlier on the iMac used as the external display. It does not work with macOS Mojave or later.

from:

Use your iMac as a display with target display mode - Apple Support

Voilà! Thanks to your reply, I successfully connected in TDM my 2020 Macbook Pro and 2010 iMac (OS Sierra) which has only Mini DV display port. I had to buy an adapter that changes Mini DV to USB C. But my other 2011, 2012 iMacs which has Thunderbolt port still doesn't work even with Thunderbolt to USB C adaptor. Apple Tech support says it's an OS software issue rather than DV port or Thunderbolt port issue (?) so if we downgrade to Sierra it'll work with other iMacs also. I'm not sure... But since only iMac (2010) that worked has Sierra and others have High Sierra or Mojave, I decided to try the downgrading the OS but I couldn't install OS Sierra even after I downloaded from App Store. it shows a message "resource is busy" I don't know what that is...

Here is what I did. It is simply a way to use the macbook keyboard to operate the imac. It wont fix what most people want to do which is to simply use the display of the iMac for their macbook. What I wanted to do was to take advantage of the nice macbook keyboard (not sure how much better it is than the imac keyboard). So I used share screen but instead of sharing my macbook screen on the imac (then there is a lag on the imac screen) I shared the imac screen on my macbook. I could then run the imac from my macbook using the nice keyboard. That of course doesn’t take advantage of the power of the macbook but it does let me use my macbook keyboard. While this may not be helpful, I wonder if it might spark off any other ideas that might actually allow us to use the imac screen for our macbook.

I am pretty sure that the reason it does not work in the 2020 MacBook Pro is that the code was removed when space in the ROM got too tight.

Since the last supported iMac was from 2014, they may feel the feature was obsolete, and used the space for something else, like supporting an iPad as display ("Sidecar").

I fully agree with Futurama77 and all others (including myself) that wrote about the TDM disappearing from our MBP 2020. I really fail to understand Apple.... Maybe they could include it with Big Sur???

Just a theory here - but maybe if you have a USB HDMI capture device you can run a a cable from your MBP to your iMac. So the signal would go:

• MBP USB-C output to:
• USB-C to HDMI adapter to:
• HDMI cable to:
• HDMI capture device plugged in to:
• iMac

Then you'd run the capture stream full screen

Dear Grant, I'm sorry it's not the iMac where the problem is. The iMac perfectly supports this function, and will do till its end of life. It's the MBP that does not support this function anymore. I have bought one in Feb 2020. It did. I was burgled and lost it. I bought exactly the same one, got it one month ago. And it does not work anymore.

It's an hardware "upgrade". That basically will make me buy another "modern" display that will never match the resolution I had on my iMac unless I pay a fortune.