2 out of 4 screens are not displaying

I purchased TBT4-UDZ specifically to be able to connect my laptop(Dell XPS) to 4 OLED TVs screens(LG TV SSCR2). Two of them connected via HDMI and two other with HDMI to DisplayPort.

My observation:

  • All 4 screens are connected however only two are active. I can display only two at the same time, while can move them around and decide which once to display out of 4.
  • I already wrote to support about 4 days ago and haven’t heard anything back.

Hi Andriy,

Thank you for posting! I am sorry things are not working fully as expected while using your TBT4-UDZ docking station, and I would be happy to help.

A quick not, previously you mentioned:

“I already wrote to support about 4 days ago and haven’t heard anything back.”

To the best of our knowledge and ability, we are unable to find any messages from your email address within our support system.

With that said and in regard to the issue at hand, there can be several potential variables that can affect the behavior of displays connected to the TBT4-UDZ.

In regard to how the displays are physically connected to the TBT4-UDZ, previously you said:

“Two of them connected via HDMI and two other with HDMI to DisplayPort.”

The cables you have with a DisplayPort connector on one end of the cable and a HDMI connector on the opposite end of the cable are most likely ‘passive’ cables, which is most likely why the displays are not working.

To expand further, the TBT4-UDZ has two HDMI video outputs and two DisplayPort video outputs. If the DisplayPort video outputs need to be converted to a different video protocol, then an ‘Active’ cable or adapter must be used. ‘Passive’ cables or adapters are not compatible.

For your reference, a ‘passive’ adapter or cable only changes the physical connection type, it does not convert the video signal. An ‘active’ adapter or cable not only changes the physical connection type but it also actively changes the video signal from one protocol to another.

An example of an Active DisplayPort to HDMI adapter would be the Plugable DP-HDMI adapter → https://plugable.com/products/dp-hdmi

Apologies again for the frustration, and thank you for giving us the chance to help!

Plugable Technologies


  1. Would this product work? I don’t mind buying yours however it might be a while before it get here.
  2. The displays are working well and I can make any screen to work(even with HDMI to DP cables) in display settings however it seems I can not get them to work all together.
  3. And another issue I noticed is with Ethernet, it does not work at all. I found a thread on your site where other people were asking about it. Followed all the steps and updated the driver and did not fix the issue.

Are there any options to get remote assistance?

Andriy Melnychenko

Hi Andriy,

Thank you for getting back to us with the update!

In response to the items you listed:

  1. We have no experience with the DP to HDMI adapter you linked to, so we cannot guarantee its compatibility or performance. In addition, the manufacturer does not specify whether the adapters are ‘passive’ (which would not be compatible) or ‘active’.

  2. If you are able to drive a HDMI display connected to one of the TBT4-UDZ’s DisplayPort video outputs using a cable with a DisplayPort connector on one end of the cable and a HDMI connector on the opposite end of the cable, then most likely the cable you are using is an ‘active’ cable (otherwise the cable would not work)

With that said, I cannot be sure of the cause of all of the displays not working at the same time based on the information available, nor can I be sure of the cause of the network issue you describe in #3.

As a result, our next step is to get some additional information.

Can you please send an email to our direct support email address → support@plugable.com with ‘For ticket #- 424797’ in the subject line that contains the following information?:

  1. The Amazon Order ID number for your TBT4-UDZ purchase

  2. While the TBT4-UDZ is connected to your computer and all of the displays are connected (even if not working as expected), the output of our diagnostic utility PlugDebug → https://plugable.com/pages/plugdebug

This information will help us to determine the next steps.

** Please do not post the above information here in our public forum (it contains personally identifiable information) **

Thank you for patience while we assist!

Plugable Technologies

P.S. In regard to your mention, Plugable does not offer any type of remote assistance support.

This topic was automatically closed 20 days after the last reply. New replies are no longer allowed.