Issue with UD3900 and USB switch between surface Pro 4 and Desktop

I seem to have a strange issue.

I have a screen that i want to share between the Surface Pro 4 and my Desktop. The screen is plugged into the UD 3900 with a DVI cable and then i plugged the UD 3900 into a USB switch that goes to my surface and my desktop. My keyboard and mouse are also plugged into the UD3900.

When i start up the desktop (which has another separate screen) it goes into dual screen mode and everything works fine. When i then click the USB switch, the surface pro 4 recognizes the second screen and mouse/keyboard and everything is fine.

Then when i switch back, the controls and mouse moves over, but the screen remains stuck on the surface, or at least the visual gets stuck on the screen because the surface wont allow access to it anymore. The mouse and keyboard moves over to the desktop pc but not the screen.

What could be causing this issue?

When it is plugged in directly, the desktop recognizes the display adaptor in device management. If i then plug it in through the USB switch it continues to work. If i press the USB switch to move it to the surface, it moves the mouse/keyboard/screen over. When i then press the USB switch to move it back to the desktop it moves over the keyboard/mouse, but not the monitor and the UD3900 does not show up in the device manager anymore.

Hi Benjamin,

Thanks for posting! Let’s see if we can identify the cause of this issue with some basic troubleshooting steps.

First, does this display issue still occur on the same port if you 1) swap the USB cables, or 2) swap computers from port A to port B? This will help isolate the cause to the USB switch, a USB cable, or a certain computer.

If the issue seems to be a certain computer, try different USB ports on that computer (USB 2.0, USB 3.0) to determine if it affects all USB ports or only certain ones.

Once I have a bit more information about the nature of the behavior, I can provide next steps.

Thank you for giving us a chance to help!



Yes, i have switched out all the cables and the cables work. The USB switch seems to work. It transfers over the mouse and keyboard that are plugged into the UD3900. The problem seems to be that once i switch the UD3900 to the surface (and it appears in the display adapter in device manager) and then switch back, only the keyboard and mouse switch back. The UD3900 does not show up again (as it did originally) on the desktop. I have also tried multiple USB ports on the desktop and they all act the same. I think the USB on the desktop might just be USB2 as it is a computer from 2012.

Thanks for getting back to me.

Does the screen freezing only occur when you switch from Surface Pro 4 to your desktop? Can you reproduce the issue in the other direction (desktop to your Surface Pro 4)?

Thank you!


It only happens when moving from surface pro to desktop. But for it to work to begin with i have to start on the desktop. I know that when i switch from desktop to surface the UD3900 shows up in display adapters. When i switch to the desktop it doesnt. IF i didnt start it on the desktop the UD3900 would not show up initially either. The only thing that switches over to the desktop is the mouse and keyboard.

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