Showing results for 
Search instead for 
Did you mean: 

DX80 as a additional monitor


I have connected my DX80 with an HDMI to DVI-D cable to my laptop docking station.  On my display settings in windows it recognized the additional display and I can drag a window to it.  However, my DX80 just shows a black screen when in monitor mode.  Anyone know what I'm doing wrong here?


3 Replies 3

Patrick McCarthy
Cisco Employee
Cisco Employee

It sounds like your laptop is seeing it as a second monitor - is that what you want? Or do you want it to just mirror the laptop display? If when you draw a window over to the DX80 it displays correctly then the DX is working fine, you need to go to the display settings on your laptop and change them to mirror displays, or if you want it as a second monitor you need to go ahead and put whatever apps/windows on that display you want to be there. If you have no background on your laptop it will just be a blank screen unless you drag something to it. 

Wayne DeNardi
VIP Advisor VIP Advisor
VIP Advisor

I have a DX80 on my desk and I'm using an HDMI cable from the docking station to the DX80 and it works great as a 2nd screen.  Make sure you have Windows set to extend your desktop to the 2nd monitor - you can use the Windows-P shortcut in most modern windows versions to toggle to the extend mode.

Note: Your question would be better placed in the TelePresence section of the forums where these devices are more actively discussed than in the Video Over IP section you've posted in - I'd suggest, if the above hasn't answered your query, that you move your discussion over there.

Please remember to rate responses and to mark your question as answered if appropriate.

Please remember to mark helpful responses and to set your question as answered if appropriate.

Steven Holl
Cisco Employee
Cisco Employee

I just had this issue on my Mac with a DX80 as a second display.  I have a 2017 Macbook with Thunderbolt 3 (USB-C), and have a 4k display coming off a OWC Tunderbolt 3 dock's mini displayport port for a main monitor. The dock does not drive a second display, and when connecting a Thunderbolt 3 (USB-C) to HDMI cable directly from the mac to the DX80, I got the display to be detected, but black screen.


The fix was to plugin the DX80 first, and then plugin the cable from the Thunderbolt 3 dock. Doing it in the other order doesn't work, and if the DX80 reboots, the dock needs to be unplugged and plugged back in. Seems to not be able to negotiate resolution when the 4k display is already active.


Kind of kludgy solution, but better than dealing with a black screen. hope this helps someone else out if searching for this issue.

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: