DTK Monitor Support (esp LG UltraFine 5K)

Can anyone confirm what displays the DTK will support? The LG 5K seems to technically only support Thunderbolt 3 input, but given its compatibility with the existing iPad Pro which only supports USB-C, I'm curious if the DTK will be similarly compatible in limited resolutions.
It depends on the model of the LG 5K. The original model is Thunderbolt only and does NOT work with the iPad Pro. The later revision added USB-C support.

I'm stuck in the same boat. My only external displays are 2 of the first gen LG UltraFine 5Ks. I'll have to wait for my DTG to arrive and see if it'll work (unless documentation gets updated somewhere) or find another monitor to use while working on that machine.
@dmoczulski thanks, that's helpful – do you know the model numbers for the before/after versions? I think the one I have (27MD5KL-B) is the new one, and (27MD5KA-A)is the older one?
@maxgoedjen Yes, you’re correct, 27MD5KL-B is the newer model that supports iPad Pro via USB-C, and 27MD5KA-A is the older model that is Thunderbolt 3 only.

Since the support document for the newer display model says that it requires a Mac with a USB-C port or Thunderbolt 3, I remain hopeful that the DTK is compatible, but I have not received official confirmation that this is so:

The new LG UltraFine 5K Display (Model 27MD5KL-B) requires a Mac with a USB-C port or Thunderbolt 3 (USB-C) port running macOS Mojave 10.14.6 or later, or an iPad Pro with a USB-C port running iOS 12.4 or later. https://support.apple.com/en-us/HT210205

Yeah, basically where I was at when I opened the thread, I know iPad Pro can power it, and Macs over thunderbolt, but what the DTK uses remains a mystery (it seems like a safe bet that it'd use a similar stack to iPad Pro, but who knows).
I do have the newer Ultrafine 5k with usb c support and that does not work with the dtk. It seems DTK only supports HDMI. I'm right now using it via VNC (of course given what I do) and will try a HDMI to DisplayPort converter later to see if I can get it to run with my 2nd 5k monitor a HP Z27q
I have a lot of monitor issues with the DTK. A basic old (spare) 1280x1024 monitor with HDMI to DVI cable does not work at all. Monitor gets in infinite loop , detected/not detected, and no signal is ever sent to the monitor.
A HDMI TV works at 1080p60 and 50, but as soon as switched to 24p or any other resolution, the same loop than above begins (detected/not detected).
Seems that monitor support is not yet mature on this box. Shame, that's exactly what I'm developing...
@steph68 I had a similar experience with HDMI-DVI conversion, and I suspect that's the problem. It worked OK with a TV set that had an HDMI port, but failed with a monitor with DVI and an HDMI-DVI cable. Of course I can't be certain but I filed feedback with details about it in case it can be fixed in an update.
I'm attempting to use:
  • 30" Apple Cinema Display

  • Dual Link DVI -> Mini Display Port adapter

  • Mini Display Port -> USB-C adapter (not Thunderbolt)

This does not appear to work and I am getting a black screen and no response.

A Thunderbolt dock does not work either, which is more understandable.

Has anyone gotten Apple Cinema Displays working?
I just bought a $300 LG 4K display. I get my DTK tomorrow but I have cables for either USB-C (Display Port) or HDMI so I hope that will work.

From what I understand, the second generation LG Ultrafine 5K will work with USB-C DP alt-mode but only at 4K.
From the document "Developer Transition Kit Release Notes":
  • Thunderbolt devices are not supported.

  • The DTK supports up to two displays: one on USB-C and one on HDMI 2.0.

    • The USB-C port supports a single display up to a 5K using a compatible DisplayPort t-mode display or adapter.

    • The HDMI 2.0 ports supports up to a 4K display.

    • Thunderbolt-based displays such as the Apple Thunderbolt Display or LG UltraFine 5K (27MD5KA) are not supported. The LG UltraFine 4K and UltraFine 5K (27MD5KL) support DisplayPort alt-mode and are supported at 4K. The Apple Pro Display XDR is supported at 5K.

My results so far:
  • LG 5K x 2K Ultrawide via Thunderbolt: failed.

  • LG 3440 x 1440 Ultrawide via miniDP through USB-C adapter: failed

  • LG 3440 x 1440 ultrawide via HDMI: works

Not ideal, but finally found a way to at least use the thing.

This is same issue with me, only the later version of the LG ultrafine is supported by the DTK, I was wondering if there are any adapters that I can use to make it work. Right now I am using Apple remote desktop to access the DTK mac mini. The other not so frugal option is to buy an Apple Pro Display XDR.


You can read the release note of DTK:

https://download.developer.apple.com/Documentation/Universal_App_Quick_Start_Program_Resources/DTK_Release_notes.pdf


Thunderbolt-based displays such as the Apple Thunderbolt Display or LG UltraFine 5K (27MD5KA) are not supported. The LG UltraFine 4K and UltraFine 5K (27MD5KL) support DisplayPort alt-mode and are supported at 4K. The Apple Pro Display XDR is supported at 5K.


I got my LG UltraFine 24" (24MD4KL-B) monitor to work by booting the Mac Mini DTK without a monitor attached and then connecting a USB-C cable while the Mini was running. As soon as I connected the USB-C cable, the LG display lit up and I was able to continue setting up the Mini. Before that, when I tried to boot the mini with the LG monitor alreaady connected, it remained black.
I only have a monitor that is LG 27MD5KA.

Has anyone try to use an adapter USB-C to ThunderBolt3?
Is there likely to be a software update soon that would enable use of the Apple Thuderbolt Display on the DTK using the Apple Thunderbolt adapter or is this impossible due to the hardware in the new Apple Silicon devices?
For anyone else who's had trouble with the DTK and an HDMI-DVI cable, please file a feedback about it. I did (FB7824785) and they asked for details about the cable. It seems like they're aware of the issue, and more reports might help.
Just thought I'd share my experience. I have two LG 27BK67U 4K 27" monitors. When I plugged in both via USB-C, only one monitor was powered. When I then plugged in the second monitor with HDMI, I got dual 4K displays running well.
I feel your pain. I have been unable to get the DTK and my LG 5K UltraFine (27MD5KL) to work together. Talk about Black Screen of Death.

I got my LG UltraFine 24" (24MD4KL-B) monitor to work by booting the Mac Mini DTK without a monitor attached and then connecting a USB-C cable while the Mini was running. As soon as I connected the USB-C cable, the LG display lit up and I was able to continue setting up the Mini. Before that, when I tried to boot the mini with the LG monitor alreaady connected, it remained black.

Very interesting. I have the same monitor but it remains black no matter what I try. You say "USB-C" cable but I think you just mean a regular Thunderbolt cable from the Mac Mini to the Thunderbolt ports of the LG monitor?
I have Lenovo ThinkVision T32H-20 connected to DTK with USB-C cable. In installation phase it needed couple power on / off for monitor to start working and the screen was newer turned off. But with the latest Big Sur beta 4, monitor works perfectly.
I'm running two Dell monitors on the DTK with beta 5. One is attached to the DTK HDMI port directly and the second is a Dell VGA display from 2004. It is attached with a VGA cable from a Cable Matters HDMI to VGA adapter which in turn is attached to the HDMI port on an OWC USB-C portable dock. Happy to find that it works. I really needed a second monitor to display documentation. I'm really glad my junk drawer paid off once again :)
I am able to drive the LG UltraFine 27MD5KL-B from DTK, but only using the included "USB-C MacBook iPad Pro" cable. The included Thunderbolt cable will not drive the display.
DTK Monitor Support (esp LG UltraFine 5K)
 
 
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