HDMI monitor flickering on and off

I’ve got one HDMI monitor connected to a laptop. Randomly the monitor shuts off for a second or two and then comes back on. Maybe once an hour or so.

This happens with two different monitors (Dell and Acer) both on HDMI. It also happens with two different laptops (Dell Win 10 and Macbook Air M1).

Is it a bad dock?


Hello Jason,

Thank you for contacting Plugable support! Sorry to hear about this issue. I’d be more than happy to assist you.

Generally speaking flickering is not a sign of a bad dock, but it can indicate some updates may be required (especially on the Windows PC side). For macOS, no updates should be required for the computer itself, so we may need to look into updating the firmware on the dock.

To get a better idea of what’s happening, since the dock has two HDMI ports, does it matter which HDMI port on the back of the dock is used for the monitor(s) that’s flickering? Or does it appear that the flickering occurs with either HDMI port, regardless of monitor model used?

There’s “Display 1” and “Display 2” for the HDMI (and DP ports):

Please don’t hesitate to let us know of other questions.

Thanks again for contacting Plugable support and best wishes!

Joshua Henry
Senior Engineer | Product Owner
Plugable Technologies

I switched from Display 1 to Display 2 and still having issues with both monitors at least with the Mac.

Thank you for the update.

As a next step since you have access to a Windows system, let’s try updating the dock firmware there. We can then see if there’s any improvement afterwards for both the Windows and Mac systems.


  1. Download and extract the firmware update folder from the zip file (EHDDPZ_Plugable_TBT3-UDZ_Update_20210716.zip). If you have trouble downloading the file just let me know.

  2. Install the Genesys Logic driver located in the unzipped folder (file name: GLUSBFLT_SETUP_V3.11.exe) and then reboot your computer when prompted by the installer.

  3. Once logged back in, connect the TBT3-UDZ to a Thunderbolt 3/USB-C port on your laptop.

  4. Run the ReadVersion.bat file in order to ensure the ICs are recognized and to determine the current firmware version. The output should read the same as below with FWVersion 8 and FWSubVersion 5. Then press any key to close the command prompt.

  1. Run the Upgrade_To_Latest_Version_V0A_1_V0A_1.bat (right click and run as administrator) file in order to update the firmware to FWVersion a and FWSubVersion 1. The output should look similar to the below screenshot. Press any key to close the command prompt.

  1. To ensure the firmware has been updated, run the ReadVersion.bat file again and the output should read similar to below stating FWVersion a and FWSubVersion 1.

  1. Now you should be able to use the TBT3-UDZ in order to see if any issues appear.

  2. Uninstall the Genesys Logic driver from Control Panel > Add/Remove programs once the flash has completed.

If this still has not helped please let me know!


Ok I’ve updated the firmware, thanks! So far so good… but will take some time to check both machines (issue only happens intermittently)

1 Like

Thanks for letting me know! Please do keep me in the loop if things change.


1 Like

This seems to have resolved the issue on my PC, but the Mac is still having issues with the monitor dropping out (static and then blank screen then reconnects after a couple seconds). Any suggestions?

Hi Jason, my name is David and I’ll be jumping in for Josh.

Glad to hear that there has been improvement with the Windows system, but sorry to hear of the continuing issues on the M1 MacBook Air.

Can you let us know the specific models of the Dell and Acer monitors you’ve used? If we have the same or similar models in our labs we can attempt to reproduce this issue since its been narrowed down to an issue with the M1 MacBook Air.

Also, can you let us know the macOS version that your M1 MacBook Air is running?

Thank you,

Plugable Technologies

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