UD-3900 stopped recognising external monitor

My UD-3900 was working fine with my external monitor on HDMI but recently stopped. I’ve tried and tested different cables between the monitor and hub and also between my laptop and another PC to be sure and all other combo’s work except anything between the hub and the monitor. Please help as running an additional cable from the laptop direct to monitor defeats the purpose of having the hub and is frustrating.

Hello Alan,

Thanks for contacting us! We’re sorry that your UD-3900 Docking Station suddenly stopped working with your HDMI monitor. I’m happy to help.

I appreciate all of the troubleshooting details you provided. You mentioned that you were able to get the monitor to work when directly connected to your PC. When the monitor was working and directly connected to your PC, were you using that same HDMI cable you originally used with the docking station or was a different cable connecting your monitor and PC directly?

Pending that information, we have a troubleshooting tool that can help us find out what is going on in situations like this. Please plug the device into your computer, then go to this page and follow the instructions there:


Once the program finishes running, please send the .zip log file it creates on your desktop as an email attachment. We’ll review the logs soon after receiving them and determine the next steps from there.

Thank You,

Plugable Technologies