3rd display (4k/Alt Mode) stopped working

Laptop: Dell Latitude 7480 - Windows 10

I was successfully using all features of my Plugable docking station (including 3 external monitors) for over a year. Within the last weeks, I suspect after some sort of system update (drivers, BIOS, not sure) the third display has stopped working. No hardware change or different connection. The display that doesn’t work is the Alt Mode (4k) port.

The DisplayLink ports work fine.

Any trouble shooting tips?

I have tried updating the display drivers (Intel HD Graphics 520) to no avail.

The key here is that it used to work. So it’s not the laptop, it’s not the cable (unless the cable has developed a loose connection?). All other functionality of the dock works fine (usb ports, audio, ethernet, both 2k monitor ports.) I am suspicious this may have happened after a system update of some sort (Bios, Windows, or Drivers) that may have been pushed to me by my IT department.

I can go into the display settings AND for the Intel HD Graphics chipset, and there is no option to enable another monitor. I click ‘detect’ and no additional monitor is detected, so I don’t think it’s a matter of configuration.

I got my IT department to let me try a spare dock, and – poof – it works. Looks like the alt mode port on that dock has gone bad. Ever seen this before?

1 Like


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

Thanks for the additional information and for grabbing a spare dock to test. I’m glad the spare dock is operating as expected. If the old dock is still non-functional after being disconnected and having a chance to reset, then we’ll want to replace it.

As with any mass produced consumer electronics product, issues can and do occasionally occur. We offer a one year warranty as standard on all of our products and will be happy to replace the dock if needed. I’ll need to collect some information to do so.

Can you please send us an email to support@plugable.com with the following information?:

-Amazon Order ID # or other proof of purchase

-Serial # off the bottom of the dock

-Best shipping address for the pretested warranty replacement

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

Thanks again for contacting Plugable support and best wishes!

Joshua Henry

Senior Engineer
Plugable Technologies

http://plugable.com | http://performance.plugable.com/

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