HDMI input not working (second screen) for HP EliteOne 870 Desktop

[courtney-a90]

I recently purchased an EliteOne 870 Desktop. I tried to plug in our second screen that we have previously used with our old computer (screen is LG Brand). When I put the HDMI cable into the back of the computer, the computer screen goes blank temporarily (indicating to me that it knows that something has just been plugged in), however it does not recognize the screen plugged in. I have tried multiple HDMI cables now. 
Can anyone please assist? Thank you.

[BeemerBiker · Accepted solution]

I am  not sure what you mean by second screen.

Anyway, looking at the folowing

HDMI-IN is port 7 and cable-tv, xbox, playstation or any type of game console can plug in 

DisplayPort (DP)) is port 8 and if you want to add an external monitor you can use that port.   If your monitor is HDMI then you need an HDMI to DP adapter.  Probably bi-directional.

This will work " connects a computer, laptop or devices with DisplayPort to a monitor,"

https://www.amazon.com/DisplayPort-Adapter-Converter-Gold-Plated-Compatible/dp/B017Q8ZVWK

[courtney-a90]

Thank you so much, problem solved! 

Purchased a HDMI to DP cable!