Target Display Mode Broken? 2018 MBPs

[PonyboyGold]

Just received the new 2018 13" MBP with the intention to use my 2012 iMac in target display mode. It worked perfectly on my 2016 MBP - but when I connect the new 2018 MBP, the iMac screen spazzes out and flickers then goes black...it seems to be a semi wide spread issue as seen in the Apple Support forums here https://discussions.apple.com/thread/8485517

Is anyone else experiencing this issue? If so how likely is this to be a software or hardware related issue? I really don't want to have to return this otherwise perfectly running machine only to have a software update come and fix the issue!

 

[AdamA9]

Just received the new 2018 13" MBP with the intention to use my 2012 iMac in target display mode. It worked perfectly on my 2016 MBP - but when I connect the new 2018 MBP, the iMac screen spazzes out and flickers then goes black...it seems to be a semi wide spread issue as seen in the Apple Support forums here https://discussions.apple.com/thread/8485517

Is anyone else experiencing this issue? If so how likely is this to be a software or hardware related issue? I really don't want to have to return this otherwise perfectly running machine only to have a software update come and fix the issue!

I think there are definitely some changes to picture output. I used to be able to set my 4k monitor to DeepColour (HDR on LG screens) but I cannot on my 2018 model.

 

[iAustralian]

Just received the new 2018 13" MBP with the intention to use my 2012 iMac in target display mode. It worked perfectly on my 2016 MBP - but when I connect the new 2018 MBP, the iMac screen spazzes out and flickers then goes black...it seems to be a semi wide spread issue as seen in the Apple Support forums here https://discussions.apple.com/thread/8485517

Is anyone else experiencing this issue? If so how likely is this to be a software or hardware related issue? I really don't want to have to return this otherwise perfectly running machine only to have a software update come and fix the issue!

I can also verify that Target Display Mode via Thunderbolt is also broken on my 15" 2018 MacBook Pro.

I have a Thunderbolt 3 to Thunderbolt 2 adapter connected to Apple Thunderbolt 2 cable connected to a 2013 iMac Thunderbolt input. On my 2016 MBP Cmd+F2 would trigger the Target Display Mode to kick in, no longer with the 2018 MacBook Pro. I just get graphic garble, colour and static.

I suspect there is an issue with the Thunderbolt controllers on the new 8th gen Intel processors. I do hope Thunderbolt Target Display Mode is fixable through firmware or software and this isn't a hardware incompatibility.

I have reported this issue to Apple, who are investigating. I suggest you do to!

Has anyone else out there got Thunderbolt Target Display Mode working on the new 2018 MacBook Pros?

 

[donawalt]

I have used Target Display mode to pull some files from a MBP 2018 from a MBP 2017, several times. It worked fine. I did not use Cmd-F2, I did it this way and it worked, if this is the same thing you are trying to do.

1. Connect the two computers with a FireWire or Thunderbolt cable.
2. On the Mac you want to use as the disk in target disk mode, choose Apple menu > System Preferences, click Startup Disk, then click Target Disk Mode.
3. When the computer has started up, a disk icon appears on the desktop of the other computer.

I also did step 2 first, then once I saw the icon (and a network icon that indicates there is no connection to anything), then I plugged in my TB cable - the second icon went away, and the disk icon showing an external disk popped up on the desktop.

Maybe this will work for you?

 

[ericbreiter]

Bump. Any update on the Target Display Mode issue? Did the recent patch help you?

 

[jcusick]

I have used Target Display mode to pull some files from a MBP 2018 from a MBP 2017, several times. It worked fine. I did not use Cmd-F2, I did it this way and it worked, if this is the same thing you are trying to do.

1. Connect the two computers with a FireWire or Thunderbolt cable.
2. On the Mac you want to use as the disk in target disk mode, choose Apple menu > System Preferences, click Startup Disk, then click Target Disk Mode.
3. When the computer has started up, a disk icon appears on the desktop of the other computer.

I also did step 2 first, then once I saw the icon (and a network icon that indicates there is no connection to anything), then I plugged in my TB cable - the second icon went away, and the disk icon showing an external disk popped up on the desktop.

Maybe this will work for you?

Dude...Target DISPLAY Mode is the problem, not Target DISK Mode. Please don't confuse them. Same thing happened on the Apple Discussion Board.