I have two monitors plugged into my Surface Pro 9 through USB-C port that works fine, when i plug them into the Thunderbolt 4 USB-C port nothing happens. Also display settings will not detect

Question

I have two monitors plugged into my Surface Pro 9 through USB-C port that works fine, when i plug them into the Thunderbolt 4 USB-C port nothing happens. Also display settings will not detect them.

Answer 1

Hi Colin Petersen

We value your enthusiastic involvement in the Microsoft Community. I'm sorry to hear that the Thunderbolt 4 USB-C connector on your Surface Pro 9 is giving you problems. Have you attempted to update your Surface Pro 9? To accomplish this, select Settings > Windows Update and perform an update search.

If that doesn't work, you can try resetting your Surface Pro 9's Thunderbolt 4 USB-C port by following these steps:

1. Shut down your Surface Pro 9.
2. Disconnect all peripherals and accessories from your Surface Pro 9.
3. Press and hold the Volume Up button and the Power button at the same time for 15 seconds.
4. Release both buttons and wait for your Surface Pro 9 to restart.
5. After your Surface Pro 9 restarts, try plugging in your monitors again and see if they are detected.

If still persists, we clear your cache on your Surface device and after try to project again to second screen.

Here's how to clear your cache:

1. Undock your Surface from the Surface Dock or disconnect the monitor from your Surface.
2. Download the Surface Dock registry file. Choose to Openthe file. This file will clear your cache, whether you have a dock or not.
3. Select and run surface dock registry.reg.
4. Select Yesto allow changes to your Surface, select Yesto confirm, and then select OKto close.
5. Restart your Surface, reconnect the Dock and/or monitors, and try your external display again.

You can also click this link for further solution. Troubleshoot connecting Surface to an external display - Microsoft Support

Let me know if you have any further questions or concerns.

Kind regards,

Christopher

Answer 2

The problem is now resolved.

I didn't change the power unit from the one the Surface Pro 9 came with, once I used the power supply unit that the Thunderbolt came with it then all work.

Thanks for the help.

Answer 3

Hello Colin Petersen,

We are happy to hear that the problem you had with [ When I plug my two monitors into the Thunderbolt 4 USB-C port, nothing happens. I have two displays plugged into my Surface Pro 9 using USB-C ports, and they operate perfectly. Additionally, display settings won't recognize.] has been resolved. We’re glad you were able to fixed the issue.

To help other customers searching for help on related issues, please feel free to mark the response you found most helpful by clicking “Yes” on the bottom of that post. This will ensure the helpful responses are most visible when searching (and you can vote more than once if the solution was spread over multiple posts).

Thanks again for choosing Microsoft!

Sincerely,
Christopher