TBT3-UD1-83 Dock makes screens flash on and off with Mac OS High Sierra

I just purchased the TBT3-UD1-83 Thunderbolt 3 Docking Station for my iMac running OS High Sierra. I have a Samsung 40" as a second display. Everything works great when I do not run thru the dock, but when the dock is used both of my screens flash off then back on every 5 seconds. Any help is appreciated.

Hi Michael,

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

Based on your description of the behavior, a few quick questions for you:

  1. Can you confirm that you are using only the Thunderbolt 3 cable included in the box with the dock to connect it to your system? I ask because other cables could cause problems.

  2. Can you provide the specific model number of the Samsung monitor you are using? I would like to look up its specifications online.

  3. Can you let me know what type of video cable (i.e. HDMI or DisplayPort) you are using to connect the monitor to the dock? Can you also let me know if you are using the included passive DisplayPort to HDMI adapter?

Thank you,

Plugable Technologies

Hi Bob,

In response to your questions:

  1. Yes, I am using the Thunderbolt 3 cable provided in the box.

  2. The TV is a SAMSUNG UN43MU6290FXZA

  3. I am using the DisplayPort to HDMI adapter provided in the box connected to a standard HDMI cable to feed the Samsung TV.

I have tried different cables and adapters, but it has not solved the issue.

Hi Michael,

Thanks for getting back with the additional information and confirmations. Looking online at the specifications for the Samsung TV, it appears it has three different HDMI inputs. May I ask you to try using the remaining two HDMI inputs on the TV to see if the behavior changes? Apologies if that request sounds redundant, but I have seen cases where different inputs on the same TV can provide different results.

Thank you!



I don’t know what they are paying you, but whatever it is - IT IS NOT ENOUGH!!!

I used HDMI 2 on the SAMSUNG and it works great! I never would have thought that changing HDMI inputs would make a difference, but it did!

Thanks for your rapid response and most excellent service!!

I will definitely be looking to Plugable for future purchases.


Hi Michael,

Thanks for getting back with the update, and you are of course most welcome for the help. I am glad to hear that everything is now working as expected, and I thank you for the kind words they are much appreciated.

If you do have the time we always appreciate reviews of our products and service on Amazon.com. As a small company we depend heavily on those reviews to help us stand out from the competition.

Thank you in advance for your consideration, and please let us know if you need any help in the future!