4K Display connected to TB3 port (using mDP to TB3 adapter) on TB3 Docking Station (TBT3-UD1-83) randomly flickers off-on

I have a Dell P2715Q 4K display connected to my new Thunderbolt 3 Docking Station (TBT3-UD1-83) using the a DisplayPort to mini-DisplayPort cable, connected to a mini-DisplayPort to TB3 adapter plugged into one of the two TB3 ports on the TB3 Docking Station.

The Docking Station is then connected to my mid-2017 15" MacBook Pro.

I also have a Dell U2410 that is connected to the dock using an HDMI cable and the included HDMI to DisplayPort adapter and then plugged into the DisplayPort port on the dock.

Additionally I have a Pluggable Super-SuperSpeed 7-Port USB 3.0 Hub (USB3-HUB7-81X) connected via the TB3 dock’s rear USB-A port.

With no identifiable pattern, my 4K display connected via the TB3 port on the docking station seems to disconnect and reconnect (basically it goes black, and then a few moments later, comes back on). The MacBook doesn’t seem to recognize it as a disconnect since it only the one display goes black, the builtin display and my 1080P display stay lit.

Wondering what could be wrong. Using the 4K display (using the same adapters) directly connected to the MBP doesn’t experience this problem.


Thanks for posting, and I would be happy to help with your docking station!

You provided some great detail about your setup (thanks for that!) but there is one detail I am not quite clear on.

When you say, “connected to a mini-DisplayPort to TB3 adapter plugged into one of the two TB3 ports on the TB3 Docking Station”, can you provide more detail about what specific device/adapter is being used?

I ask because it does not sound like a Plugable product, and I want to be sure I understand precisely how things are connected.

Thank you,

Plugable Technologies

The USB-C to Mini DisplayPort adapter is not a Pluggable product. This adapter is made by ITANDA. http://a.co/1H7qTHD

Here’s a picture how I have it all connected.

Thanks for getting back, appreciate very much the link to the adapter used and the photo of your setup.

We don’t have the adapter you are using in our lab to test, so unfortunately we can’t speak to its performance with our product. Given that the behavior is only affecting the display connected using that adapter, I would suspect the Itanda adapter itself as the culprit.

In an effort to test this theory, I would like to send you one of our own USB-C to DisplayPort cables (http://plugable.com/products/usbc-dp) free of charge to see if the behavior changes. If you could just send the following information to support@plugable.com (don’t post these details in the public forum) with ‘For Ticket 192329’ in the subject line I can get that process started.

  1. Amazon Order ID number for the Plugable Dock purchase (available from http://amazon.com/orders)
  2. Serial number from the bar code on the bottom of the dock
  3. Full shipping address including name

Thank you!