Video output / display function stopped working. Other UD-3900 does work OK on same computer

Recently I bought 2 UD-3900 docks for my laptop:

  • 1 for the office
  • 1 at home
    Both worked great for 2 months, until one of them stopped working 2 days ago.
    Reïnstalled software:
  • 1 is working OK
  • 1 is not working OK (video output)
    Exchanged the docks with the monitors attached:
  • same not working dock: no video output anymore
  • when I attach the dock with the video out problem: Windows 8.1 device manager reports an USB problem
  • when I attach the good working dock, device manager does NOT reports an USB problem

My conclusion is a defect video chip.

Hi Hans,

Thanks for posting here! Just shoot us an email at with your amazon order ID and a link to this thread and we will take care of the issue.