I guess the new ones don't put out enough power with HDMI to support the extra device.
That's an interesting observation. Perhaps test Thunderbolt out to the HDMI Detective? Might be worth trying the Detective with this $7.50 miniDP to HDMI adapter and your 2012 Minis to see if you still need the power supply.
I would have expected as you did that behavior to remain with the 2012 revisions.
I wouldn't have...the HD 4000 graphics and drivers were new to the 2012 Minis, the first version of something major like that is always a roll of the dice with Apple...and there had already been reports of similar behavior on the Intel forums being noticed by Windows PC users w/ the HD 4000.
I wonder if that may be behind some of this display flickering and other items people have had issues with.
Right, not just display flickering, but random black screens, blank screens and snowy screens:
and not too long ago Apple released an EFI update, which cleared some, but not all, of this up. Was this already updated for you?
Are you seeing any of that behavior with
the Detective plugged in? Or is your main issue not wanting to keep the Detective plugged in?