Target Display Mode not working 2020 MacBook Pro (Catalina)

thanks Grant but it's not. Purchased in 2020 but it's identified as a specked up 2019 model in the 'about this mac' window. I've tried a number of fixes including osx re-install and exhausted options according to apple support with recommendation to use screen sharing (which you also linked to earlier) which I've found to be an unsatisfactory user experience. The imac continues to work flawlessly in TDM with the 2015 mbp running sierra!

Are you also running High Sierra or OLDER on your iMac? and the recommended cables from that article?

If that is the case, and it is still not working for you, applying pressure to Apple MAY get them to fix the feature. But it is FAR more likely they would "FIX" the documentation to include that your case does not work either.

Okay thanks Grant, I'm running Catalina on the imac but will try a reinstall of high Sierra. I assumed that while running Catalina, since it was still working in TDM with my 2015 MBP that the 2019 MBP should connect also. I'll get back to you on this. Thanks for the tips.

Same issue here. Just wanted to add it also applies to the new 2020 iMac 5K. I can't use my old iMac mid-2012 as a target display anymore. Frustrating, and so much time wasted trying to figure this out!

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").

Just adding another voice to the chorus. It's my new MacBook Air, not MBP, but I'm equally frustrated and out-of-pocket on cables etc., as well as having spent 3 or 4 hours with Apple support on the phone before sale and after, trying to make this work.

This problem is beyond frustrating. I have a 2020 Macbook Pro and a 2019 iMac. Both have the Thunderbolt 3 (USB-C) ports (on MBP that's all it has) so I got the Thunderbolt 3/USB-C cable to connect the two together so I can use my iMac as display for the laptop. Nothing worked, including the old 'Command + F2/+FN and F2' and reading this thread, it looks like both the newer iMacs AND the newer MacBooks don't support Target Display Mode. What!? How am I supposed to use this in the office with other external monitors? Or even now just working from home? Ridiculous, this is such a basic computer feature and Apple took it away quietly, thanks a lot.

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???

The last supported iMac was the 2014 model. That is getting old. Odds are not good that this feature will be seen in any future product.

Luckily, modest displays that can do the job are getting really cheap by historical measures, or HDTV set can be used. Or use your iPad is "Sidecar" mode.

Now I understand why my work laptop - a 2019 MacBook Pro works with my 2013 iMac in Target Display Mode but our new 2020 MacBook Pro does not. So frustrating! They have the same OS and almost identical capabilities. Why did Apple do this to us?

I have this exact same issue. What a huge disappointment. Apple is this true? Can you contact me if it’s not?

I’ve tried everything! I meet all the other requirements for macOS version, using all Apple cables, I’ve spent $$$$$ trying to get this to work as advertised and 10+ hours of my time! Will Apple saw my iMac for a mid 2014? So it will work?

Sam here I was gonna buy iMac 2020 but returning it as I have macbook pro 2020 and would have loves to use it as external monitor and my video editing setup. I hope the "target display mode" comes back.

dagmarpiano71 wrote:

• 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

Based on Apple articles and the way Mac display interfaces work, that "solution" does not have a prayer of working "just with cables". it requires stunt-box with the equivalent of a display interface inside it. Pricey.

That proposed solution could only work with a special-purpose Video capture device. That money would be better spent on a new display.

I did something similar that worked with very low latency attaching a PS4 to my iMac using an HDMI lead and gamers' video capture card. It was only 1080p but that could be workable and maybe modern capture devices can do better.

In any case I said it's just a theory. I would try it myself but I don't have an old iMac to test it with.