UD-6950 Display cuts out on mac

Hi. I’m connecting a dell display to the 2K output via HDMI. When I plug my computer in sometimes the monitor works sometimes it doesn’t. after i unplug the dock, disconnect my computer a few time is works again. I don’t understand what could be causing it to cut in and out. I might be there there is a loose ground connection in the dock, when i touch the dock itself it cuts out the monitor.

Hello Sam,

Thank you for contacting Plugable support! Sorry to hear about this issue. I’d be more than happy to assist you.

You mentioned the 2K HDMI output - the UD-6950 has dual DisplayPort outputs, do you actually have our UD-ULTCDL or UD-ULTC4K dock?

Either way, it certainly sounds like it could be a hardware problem hearing that touching it causes the monitor to cut out. Are you connecting the dock to the Mac using the USB cable that the dock shipped with?

Does the other HDMI connection (4K) work OK? (assuming you have the UD-ULTCDL)

Please don’t hesitate to let us know of other questions.

Thanks again for contacting Plugable support and best wishes!

Joshua Henry
Plugable Technologies

Hi Joshua!
Thanks for the quick response. It does have 2 outputs. 2k HDMI and DVI then a 4K. I have never been able to get the 4K one to work, I just thought it didn’t work with my monitor. I uploaded a pic, did you get it? I think the problem is a ground because when i put my hand on the top of the dock everything cuts out. the little green USB light in the front also goes off. The cable I’m using is a thunderbolt 3 cable from belkin. What do i need to do to get this issue fixed? Can i get a replacement unit?



Thanks for the info and the picture. Are you able to try the original USB-C to C cable the dock shipped with to rule out any potential issues using the third party cable? It’s possible the dock is at fault, I just want rule out the third party cable first.


Hi Josh,
Yes, I have tried both cables and a hard drive cable i have here.


Please contact me directly at support@plugable.com and we can arrange to send a pretested replacement under warranty. I require your Amazon Order ID # or other proof of purchase, the serial # off the bottom of the dock, and the best shipping address.