First time poster, if this belongs somewhere else/isnt allowed please be patient with me Hi, I have used my 2012 Mac Mini (MD387LL/A) with my 27 inch LG monitor (27MP33HQ) for years without any problem, but recently I've picked up a Samsung 24 inch curved monitor (CF390 24'') and wanted to run dual monitors. I have had my 27inch monitor plugged into my mini using the standard HDMI port on the back of the machine, and I have had a spare mini display to HDMI adaptor (Sabrent Mini DisplayPort (Thunderbolt) to HDMI Adapter [4K Support] (DA-MDHA)) lying around and thought I would just plug that into the back of my mini and plug an HDMI cable from that to my second monitor. So whatever monitor is plugged into the main HDMI port on the back works fine and is detected, but whatever is plugged into the mini display port using that adaptor does not. Its not detected, no signal, etc. I then plugged the adaptor into my macbook air and to a monitor and it works fine, no problems at all. I did a little research into passive and active mini display port adaptors and thought maybe my adaptor was passive and wasnt allowing a connection. So i ordered (Active Mini DP to HDMI, CableCreation 6 Feet Mini DisplayPort (DP1.2) to HDMI Cable, DP to HDMI, 4K X 2K & 3D Audio/Video, Eyefinity Multi-Screen Support, 1.8 Meters/Black) a new adaptor and when it came in im still having the same issues, nothing connecting to the mini display port is detected. With the first adaptor (sabrent) whatever was plugged into that adaptor, when you turned it on both monitors reset and would sometimes turn the main monitor (whatever was plugged into the HDMI port on the mac mini) into a blank black screen after flashing for a second. Then when you turn off the monitor thats connected through the adaptor the main monitor turns back on. I have swapped out HDMI cables, I have tried both monitors in several different combinations, and now i have tried two different kinds of adaptors. I have completely shut down my mini and turned it back on, its on the latest OS as of 9/19/2018, i just do not know what to do.