One monitor not working, of three

Hello I recently tried to use the UD-ULTC4K with my existing set-up, an ASUS VivoBook F510UA.with three Acer EB321HQ monitors. I have downloaded the newest software, tried multiple un-plugging and restarts and of the three additional monitors, monitor 1, or HDMI 1 does not work. The laptop, and HDMI 2, and 3 work. but I cannot get HDMI 1 to work. Any help would be appreciated. Thank you.


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

Unfortunately, your ASUS laptop does not support the required USB-C DisplayPort Alternate Mode video output technology that is required to drive the primary 4K HDMI port on the dock. This feature is optional per the USB-C specification and not all computers with USB-C have this. As such the dock will be limited to two displays with this model computer. Sadly, USB-C DP Alt Mode video support cannot be added to the computer.

Per the ASUS documentation this C port is for USB data only, and does not output video:

If three displays are required, you may need to connect the third directly to the laptop instead via the built in HDMI port. Or, alternatively, you can use an additional USB graphics adapter connected to the dock via USB to bypass the HDMI 4K port since it’s not compatible with your computer. For example, our UGA-2KHDMI adapter would work to add a third 1080p screen through the dock for use with this ASUS system:

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

Thanks again for contacting Plugable support and best wishes!

Joshua Henry
Senior Engineer | Product Owner
Plugable Technologies

Thank you, Joshua.

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