MACBook Pro 13" Mid 2012

Hello. I just recently purchased the UD-3900 and the switch to accompany it. My external screens keep going black after a few seconds.



Thank you for contacting us, I am sorry this is not working as expected and I am happy to help!

When you have a moment please let me know the specific version of macOS installed on this computer.

  1. Open the Apple Menu > About this mac…
  2. Please let know the system model details and macOS version from this page
  3. Please feel free to attach a screenshot of this window to your reply email if you prefer by using the macOS screenshot hotkey combination [Command ⌘]+[Shift ⇧]+[4] then dragging a selection box around the window, the screenshot will be saved to the desktop and can then be attached to your reply email.

and the switch to accompany it

Is this our USB3-SWITCH2 USB 3 Sharing Switch ( )? If so is there a second computer connected to the switch and are the displays stable on the second computer?

Please try connecting the docking station directly to the 2012 MacBook computer, bypassing the switch, and let me know if the displays continue to reset, or if this stabilizes the external displays.

Thank you, I look forward to your reply and we can proceed from here.

Plugable Technology


We’re closing this thread due to inactivity, but if you have any further questions please feel free to contact and we’ll be happy to help.


Plugable Technologies