Have a late 2012 Mac Mini. Have a Apple Thunderbolt Display as my primary monitor and have a old Dell monitor I want to connect. It has a VGA cable and I have an Apple VGA to mini display adapter. I have tried using that VGA to mini display adapter setup, but it doesn't seem to work. I have the mini display adapter plugged into the back of the Thunderbolt display, as the Thunderbolt display is plugged into the Mac Mini. Am I doing things wrong?