Thunderbolt 4 display not working on Maximus Z790 Hero

[cboyan]

I am trying to get a second monitor running using the Thunderbolt 4 port on the rear panel.  I have tried 3 different Thunderbolt-to-HDMI adapters and they all behave similarly.   

1. The "Thunderbolt (TM) Controller - 1137" item under System Devices in Device Manager remains grayed out (you actually have to enable Show Hidden Devices to see it all) but under Properties says "Currently, this hardware device is not connected to the computer"; driver version 1.41.1335.0:

Attempt to update the driver says the most current driver is already installed.

2. The Samsung M5 monitor that I am connecting to shows up under Digital Media Devices but not under Monitors

3. There is no "Monitor 2" available under Display Settings.

4.  The monitor keeps turning on, timing out, then turning on again, so I know SOME communication is taking place.

5.  The Thunderbolt Control Center shows no attached devices and Controller Driver Version is N/A

I am running BIOS version 2108 and WIndows 11.  

Any help would be appreciated

[Jiaszzz_ROG]

Hello @cboyan 

Thank you for reaching out to us.
Based on the model information you provided, it appears that the Samsung Smart Monitor M5 does not support input signals via Thunderbolt or USB Type-C. Although this is not clearly stated in the specifications, we were able to confirm it through the support section on the vendor’s official website.

We kindly recommend cross-testing with a different monitor to further isolate the issue. If possible, please also try using the official cable that came with your monitor, or an alternative cable, to verify whether the connection method may be contributing to the problem.

Thank you.