Apple Cinema Display (mDP) connection issues

I am having some challenges with connecting different machines to an Apple Cinema Display (I have two of these, so I can test against both). Today I have had some issues connecting a Mac mini.

Over the last few months I have been troubleshooting connecting a PC the Cinema Display. There is a discussion about this here…

I thought it might be the graphics card (Nvidia EVGA GE Force 770 4GB) or the cables (DisplayPort to Mini DisplayPort adapter, Mini DisplayPort extension cable), and was entertaining buying a seperate monitor for the PC.

I moved house recently, and in the process of setting up my office, I connected the Mac Mini — which I normally run headless (Plex media server, etc). Using the Mini DisplayPort cable from both Cinema Displays there is no signal (it was connected to a TV via HDMI with no issues a couple hours ago)

I connected my new MBP (with touch bar) using an adapter recommended here

and the Cinema Display immediately comes to life (appreciate the recommendation @jaysee)

I had initially thought that with the PC, the sporadic display output (mentioned in the other thread) might be linked to nothing being connected to the Cinema Display power pass through — some times when I connected a (different) MBP to power to the Cinema Display it would come to life, at other times it would not.

As I am having similar issues with the Mac mini, can anyone offer a suggestion on how I might work around this and have the Cinema Display work with the Mac mini and/both the PC??