UD-3900 PDZ, HDMI-1 will not work


I just received my UD-3900 PDZ, all plugged and powered. HDMI-2 &3 are working fine but HDMI-1 will not work. I have updated the displaylink drivers but this has had no effect. can you assist ?


System Model >> HP Laptop 15t-dy500
System SKU >> 667A5AV

Hello Monica,

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

Unfortunately the HDMI 1 from our UD-3900PDZ dock will not function with your computer as your computer does not meet the minimum requirements to support this dock. Per the HP specifications it only offers a “data-only” USB-C port which cannot support the HDMI 1 on this dock.

For reference per HP:
“(1) USB 3.2 Gen 1.0 Type-C port; 5 Gbps signaling rate (data transfer only; charging or external monitors not supported)”

This is ultimately due to USB-C video (“USB-C DisplayPort Alternate Mode”) being optional per the USB-C specification and some computers do not offer it as such.

You computer does appear to have an HDMI port built in, you may need to either attach your third display there, or we could bypass the HDMI 1 on the dock since it is incompatible with your computer’s limited USB-C port and use a separate USB graphics adapter connected to the dock instead.

For example: https://plugable.com/products/uga-2khdmi This adapter would allow another HDMI monitor to connect through USB.

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

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