Using my HP all in one as a secondary monitor

[dygla67]

I had a 24 inch HP all in one but upgraded to the 27 inch.  But I see now that I don't have an HDMI in port, does that mean I can't use this in any way as a second monitor?  I hooked my work laptop up to the 24 inch and it worked as my second monitor.  I can't believe this doesn't work.  I will have to return this .  So frustrated.  

[itsmyname]

@dygla67 -- I had a 24 inch HP all in one but upgraded to the 27 inch. 

But I see now that I don't have an HDMI in port, does that mean I can't use this in any way as a second monitor? 

Unfortunately, "yes", since your computer does not have a "video-input" port.

I hooked my work laptop up to the 24 inch and it worked as my second monitor. 

Yes, the "video-out" from the laptop was cabled to the "video-input" on the 24-inch All-In-One.

Presumably, both the 24-inch and the 27-inch each have one "video-output" port.

I can't believe this doesn't work. 

I can believe that the 27-inch does not have a video-input port.