Level 1

59 points

2018 MacBook Pro Target Display Mode Not Working

Has anyone successfully used Target Display Mode with the new 2018 15" MacBook Pro? We just purchased one last week, and I am trying to use a late 2013 27" iMac as a second monitor via Target Display Mode.

When I hit command-F2 it does try to switch over, however the screen either a) remains black b) shows my screen but blinks every other second c) shows the screen but it's static-like and has crazy zig-zag colors across the background and flashes and such.

I have done all the recommended trouble shooting steps per the knowledge base article and am wondering if this is a problem with the new MacBook Pros. It is very frustrating to not be able to work on my brand new computer; I need the larger monitor for graphic design.

Both have latest versions of High Sierra. I have tried two different Thunderbolt 2 - USB-C adaptors. I have tried two different Thunderbolt 2 cables. One I have used for four years so I know it works. I have reversed the cables and tried all the different Thunderbolt ports on both machines. I connected them using Target Disk Mode to transfer my data and that worked.

I reset the SMC and zapped the PRAM. I booted in safe mode on both machines and then restarted. I have spent a good bit of time on this, but since this is a work machine I can't keep wasting time on it as I need to actually get work done, which unfortunately means still using the older iMac.

Any other thoughts?

MacBook Pro (15-inch, 2018)

Posted on Aug 2, 2018 7:53 AM

Top-ranking reply

PENG ZHAO

Level 1

18 points

Posted on Sep 12, 2018 1:15 PM

hey guys, just want to confirm that I used Belkin Thunderbolt 2 Express F4U085TT to connect my MacBook Pro 2018 with an iMac 2013. The iMac can be used as a target display. No flickering, no dark display. It just worked flawlessly.

Basically, you need a Thunderbolt 3 to Thunderbolt 2 adapter and the Thunderbolt 2 cable that comes with the dock to connect your MacBook Pro to the dock. then need another thunderbolt 2 cables to connect the dock to the iMac. I know it sounds stupid but it works.

View in context

224 replies

Aug 16, 2018 11:28 PM in response to Pennock

Hello,

Yes I did. Called yesterday and was on the phone for over and hour with Support. Got it escalated and they said they would have to get back to me because it would require more research on their end. I told them about the hub, and they said that was good info. But, still no solution and it’s very frustrating.

Aug 19, 2018 3:02 PM in response to randeerod

Target Display Mode software , like target Disk Mode software, is the displaying computer's ROM.

it does not depend on any MacOS, and in fact should work if the displaying Mac does not even have a disk drive installed.

So 'what version is running on the displaying computer' is a complete distraction -- it has no bearing whatsoever.

Larszoon

Level 1

19 points

Aug 20, 2018 12:51 AM in response to Pennock

Unfortunately I have the same problem with my brand new 2018 13" MBP 😟

Configuration I'm using:

Apple Thunderbolt Cable
Apple Thunderbolt 2 to 3 (USB-C) Adapter
2013 iMac 27"
2018 MacBook Pro 13"

Is there an update coming soon? The beta of macOS Mojave 10.14 doesn't seems to fix the issue. Or do we have to wait for the official release!

TayDC

Level 1

28 points

Aug 31, 2018 11:18 AM in response to JeffQ6

Glad you got your set up worked out! That being said it would be ridiculous for the rest of us to have to buy a thunderbolt dock in order for TDM to work properly, not after spending so much on these new machines. I certainly don't want to have to buy a new monitor and have may iMac go to waste - this is on Apple to figure out, at the very least it would be nice to get an official response.

applelas

Level 1

4 points

Sep 7, 2018 9:17 PM in response to Pennock

It seems that for now the target display mode is not working on the new MBPs, however there was a reference to an expensive hub that would allow the target display mode to work - what is that hub? There were also references on possibly daisy chaining the computer you were using TDM on to the other monitor so it could be used again does anyone have directions on how to do that?

Thank you

Sep 9, 2018 4:56 PM in response to TayDC

TayDC wrote:

Now that is weird! Apple discontinued TDM on iMacs post 2014, so the fact that it works on the iMac Pro is certainly a surprise

The iMac Pro is using a 2013 iMac as an extra display. The 2013 iMac is in Target Display Mode, not the iMac Pro.

Sep 10, 2018 8:50 AM in response to atousceux

Could you please let me know the product information of that Belkin thunderbolt dock you were using?

I tried Apple thunderbolt 3 to thunderbolt 2 adapter, it only worked on MacBook Pro 2016 not 2018.

Thanks!

Larszoon

Level 1

19 points

Sep 10, 2018 9:13 AM in response to Pennock

During my preparations for the upcoming phone call with Apple Support I've tried to connect the 2018 MBP with my Late 2013 iMac 27". Guess what... the connections is working! However it's not stable and the display blinks regularly for 5 seconds. Waiting for the call now. Give you an update later.

Sep 16, 2018 9:59 AM in response to Pennock

I'm having the exact same problem, I contacted customer support and I have yet to receive an answer on this issue. I even provided a video of the issues that I'm having while using target display from new 2018 MacBook pro to my 2011 iMac. Maybe their recommendation will be for me to buy a new iMac? 😠

wadeopgh

Level 1

4 points

Sep 17, 2018 6:55 AM in response to StephenOtalora

"Maybe their recommendation will be for me to buy a new iMac?" - I believe since 2014 the new iMacs do not support Target Display Mode, so they will not suggest that you purchase a new iMac maybe a new monitor.

They should have it resolved soon

wadeopgh

Level 1

4 points

Sep 19, 2018 10:08 AM in response to researcher_ash

This thread is for Target Display Mode NOT mini display port out, researcher_ash...

Most of the people on this thread are interested in using TDM on their 2010 -> 2013 iMacs. I think before 2010 and after 2013 they do not have TDM. I would only go about what researcher_ash says if you're having the exact issue with the same setup that he has. I'm following up on this thread as I do not want people thinking this will solve their issue connecting to 2010 -> 2013 iMacs.

If I'm wrong about this please follow up as I would love to resolve this ASAP and I'm still in my return window for the Apple Thunderbolt 3 -> 2 adapter. But from what I have read and research that I have done it will not.

Sep 19, 2018 1:10 PM in response to wadeopgh

Hi. Yes ok. I had thought my iMac, the late-2009 27", was automatically going into TMD when a mini Display feed was stuck into it. But if it's not then sorry to get anyone's hopes up. I wonder what it is then other than a TMD process?

Sep 29, 2018 3:14 AM in response to Pennock

Exactly the same problem for me. I've spent hours with technical support without any success.

Tried different 3rd party adapters but still no luck.

Apple, please sort out the problem.

MacBook Pro 2018 15" i9 + iMac 28" mid 2011 with i5

thanks,

Waldemar

Sep 29, 2018 10:02 PM in response to 55eba

Thunderbolt iMacs require a Thunderbolt cable for Target Display Mode. A Thunderbolt port (except that on the back of a Thunderbolt display) can be used for video output with a Mini DisplayPort cable, but video input requires a Thunderbolt cable.

Oct 2, 2018 7:50 AM in response to Pennock

macOS Mojave is out. I downloaded it on both my MacBook Pro and iMac with a faint hope there might be a fix. Not surprised but saddened that there is still no fix. It is obvious this is not a priority for apple, I don't even think anyone is working on it. Prove me wrong Apple, please fix this.

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2018 MacBook Pro Target Display Mode Not Working