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

Jan 8, 2019 11:34 AM in response to katbay

katbay--

What an ordeal!

And now what a Triumph to have beaten the machines and have this working!

Congratulations!

katbay

Level 1

8 points

Jan 8, 2019 11:40 AM in response to Grant Bennet-Alder

Yes. Quite the ordeal. However, so far, I'm troubleshooting far less than I had to 10 or 20 years ago! And FAAAR less than 30 years ago! Thanks again! Woohoo!

Feb 14, 2019 10:43 AM in response to documental

Has it worked with older MBP's? Assuming you are using a thunderbolt cable and not a mini display port cable. The iMac I'm using is a 27 inch running El Capitan.

Feb 14, 2019 4:41 PM in response to katbay

Yeah, sorry for not explaining better, but I have done that and it hasn't made a difference! Here is how it looks, and has looked.

katbay

Level 1

8 points

Feb 20, 2019 2:19 PM in response to Aron Downie

Probably doesn't matter, but my MBP is running latest Mojave, and iMac is running High Sierra.

nnmnnm

Level 1

4 points

Apr 9, 2019 12:27 PM in response to PortDover

Same issue here. Both, the 2013 iMac 27" and 13" 2018 MBP are on 10.14.3, Apple Thunderbolt Adapter and Cable for bunch of money and nothing works. Just black screen after CMD+F2 :(

Aug 13, 2018 6:56 PM in response to Pennock

I am also having this problem. I chatted with about 5 different Apple advisors and no fix did the trick. I was told to call back and report a diagnostic so that the engineers could look at the problem, so we’ll see what happens I guess. I’m really missing the ports from my older MacBook Pro.

Aug 13, 2018 6:59 PM in response to therealmitcherz

Regarding the ports, do you use the laptop in one place most of the time or are you constantly on the move? There are a multitude of great docks out there. I use one that charges my laptop and connects an external mouse, keyboard and connects my laptop to the internet via Ethernet for faster speeds.

Richard

Aug 14, 2018 4:10 AM in response to Pennock

I'm having exactly the same problem as initially described. Target display mode worked perfectly on my 27" late 2013 iMac combined with an older MacBook Pro Late 2013 as well as with a MacBook Pro 2017. Just with the MacBook Pro 2018 I'm having that weird flickering issue that's makes it unusable. Would be a real bummer and reason to return the new MacBook Pro if Apple can't fix this via an update! More and more you get the impression that they no longer thoroughly test their products before releasing them... 😟

TayDC

Level 1

28 points

Aug 17, 2018 6:37 AM in response to Pennock

I finally received a call back from a Genius at Apple who passed on a message from an Senior Engineer. He claims my 2012 iMac is incompatible with the new models. This makes absolutely no sense as it is 100% listed as compatible in the Target Display Mode info page on Apples site. The fact that there hasn't been an official statement by Apple yet is ridiculous..I am now outside the return window (my fault I suppose), but I don't believe that answer I just got. My iMac isn't the problem, there are too many of us with identical issues with the new 2018s...

Pennock Author

Level 1

59 points

Aug 20, 2018 7:06 AM in response to Larszoon

Larszoon - Shoot, I was hoping Mojave would fix it.

It doesn't sound like anyone has gotten an official response from Apple, we all need to keep bugging them, submitting tickets and following up. If you get an unsatisfactory/untrue response like some have (your iMac isn't supported) just try again. I know that can be tough as for a bunch of us these are work machines and you can't really sit on the phone for an hour while at work. Chat is a good start, but once they escalate it you have to get on the phone. Just do what you can, every submission helps!

Does anyone know how to notify those sites that do Mac news, or reviews of the new laptops? Maybe some negativity on the reviews would light a fire under Apple? I think someone said they tried this a few weeks ago but maybe there would be better luck now that more and more people are affected by buying new machines.

Aug 21, 2018 7:17 AM in response to sforner405

Thunderbolt 3 to Thunderbolt 2 Adapter
Maybe this one works.

No, no, no ...

Those ThunderBolt 3 to 2 adapters do not present ANY directly-usable display interfaces.

To connect to a Mini-DisplayPort display, you must use an adapter specifically for the conversion you need, and it must be complete in ONE adapter.

So you must have something that says "ThunderBolt-3" on the computer-end, and "Mini DisplayPort" or exactly what you need on the display end.

"Stacking" display adapters is seldom successful.

But this is not the main topic of this thread, it is a side issue.

Aug 28, 2018 4:10 PM in response to Pennock

Hey community, I have the exact same problem. New MacBook Pro 15" i9 and I try to connect my Late 2013 27" iMac. Changed adapters and cables already and had a meeting at the Genius Bar today. The guy was very nice and tried everything. It worked perfectly with their external monitor. Unfortunately they didn't have an iMac available for a test. He asked me, that he will open a case with Apple support..... Hopefully someone will figure it out. After spending 4,300$ for my new MacBook I don't want to spent another $1,600 for a new monitor... Any help is much appreciated. Thanks all of you. Best CW

pg@cfit

Level 1

4 points

Aug 31, 2018 1:18 AM in response to Pennock

I'm also experiencing this issue. I have access to several iMacs at work, and three thunderbolt cables. All iMacs are capable of Target Display Mode and work as an external monitor if I connect them to a 2016 MacBook Pro. They *all* fail to work with my 2018 model.

The latest supplemental update to High Sierra doesn't address this issue. I filed a Radar (43929442) and contacted Apple's customer service. They asked me to update the OS on both devices, to use different cables (if possible), and other things that seem like the "list of things to try". After we exhausted the list I was asked to take my devices to an Apple Store (or authorised repair center)... which I haven't done because I found this thread and have determined that this probably isn't a problem with my MBP.

Sep 13, 2018 10:13 AM in response to researcher_ash

Reply to self.

With SMC reboots of both computers there's been no change.

Have been asked to take new MBP into a genius bar. No way. I kept mentioning this forum and that Apple engineers could easily replicate the issue the their labs. Taking a call back tomorrow and will report but likely no change.

With research I find that Thunderbolt 3 can only transform itself into Thunderbolt 2, VGA or HDMI. To get other signals from these MBP ports is to obviously use them as USB-C but USB signals can't support monitors (I don't think).

Question is: whether to sell the iMac and buy a new screen that takes HDMI? Maybe.

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2018 MacBook Pro Target Display Mode Not Working