HDMI 1 doesn't work

HDMI 1 does not display an image, HDMI 2 and 3 Both work, i have switch my monitors around between each, all the monitors work on 2 and 3, but nothing works on 1. Dodgy connector? looking for a Displayport cable, but kind want the HDMI to work (considering its brand new).


Thank you for contacting Plugable! I am sorry one of the HDMI ports is not working as expected while using your new Plugable UD-ULTC4K docking station, and we would be happy to help.

The HDMI port labeled “Alt Mode” requires specific functionality to be available from the laptop’s USB-C port and the cable that came with the dock must be used.

Do you happen to know if your laptop supports DisplayPort Alt Mode video output from the USB-C port and can you confirm you are using the USB-C cable that came with the dock?

If you are unsure if your laptop supports video output from the USB-C port can you tell us the brand and specific model? We can assist in looking up specifications.

We’ve also received your message from the Amazon Marketplace messenger and we will merge these two support cases together to keep all details in one location.

Thank you,

Plugable Technologies

the laptop is an Acer Nitro 5 AN515-45-R5G6.

I am using the USB-C provided.

im looking now to see if it supports DisplayPort Alt over USB-C. i did say a vague comment that it might not support it, but at the same time ports (and monitors) 2 and 3 work over the USB-C, though ill be honest im a little out of my depth with this display link technology.

Hi Andrew,

Thanks for the update.

I am having a bit of trouble confirming information about the specifics specifications of the USB-C port. However, the information that I have found does point to the USB-C port on the Acer Nitro 5 AN515-45 being data only and not supporting the required DisplayPort Alt Mode for extending displays.

Since the HDMI 1 connection requires that the host computer has a USB-C port that supports DisplayPort Alt Mode, this would explain why that display connection is not working when connected to this laptop.

Since I’m finding it difficult to verify this information through the Acer website, it may be worth contacting their support to get clarifications as to exactly what the USB-C port on this computer is capable of.

Thank you for giving us a chance to help and please let me know if you have any questions.

Richard A
Plugable Technologies

If i was to return it and buy a two slot one would i run into the same issue? like by default is HDMI one on all of the models alt? cause like i said HDMI 2 an 3 are working with my laptop, and i plugged my third screen into the laptops own HDMI.

Id prefer to return it and it save the £100+ or so, but at the same time im now nervous that the 2 slot wont work and then i wont be able to use my third monitor at all.

Hi Andrew,

Thanks for the update.

Looking at your previous ticket, you should still be within the initial 30 days of purchase and Amazon should allow you to return that docking station.

When it comes to compatibility for this computer, you will want to look at our docking stations that use DisplayLink connectivity over USB 3.0 in order to be most compatible with this laptop.

Here is a link to the category of docking station that would best to suit this computer:

Essentially, these are two display docking stations that are very similar to the one you already have but they do not utilize the Alt Mode connection, and they do not have the ability to charge the laptop battery.

I hope this information is helpful, and please let us know if you have any additional questions.

Richard A
Plugable Technologies

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