Connecting Mac mini M4 to older displays

Your M4 mini does not support the older, long-obsolete Apple Displays. Furthermore, Apple does not sell or support adapters that overcome this limitation, unfortunately. Be wary of discussions including those on the internet that claim otherwise. FWIW, you can follow this discussion Unable to connect Apple Thunderbold Displ… - Apple Community but with the usual caution including fine print issued by Apple at the bottom of this page...

...all the best.

shervinia wrote:

I’m trying to connect my just purchased Mac mini M4 to bothmy old 27 inch Thunderbolt Display as well as my 23 inch Cinema Display.

I got a new thunderbolt 3 to thunderbolt 2 connector on eBay. Said it was original Apple product but the display did not work.

Is that an Apple Thunderbolt Display (model A1407), with a two-headed hydra cable, a FireWire 800 port, and an Ethernet port? Or is it a LED Cinema Display (27-inch) (model A1316), with a three-headed hydra cable?

The Apple Thunderbolt 3-to-2 adapter only translates Thunderbolt and will not offer the plain DisplayPort signal that the LED Cinema Display needs.

If this is a Thunderbolt Display, but things still don't work, it could be that the built-in hydra cable is bad, or flaky. You can sometimes get around that by running a Thunderbolt 1/2 cable from the TB2 side of the Apple TB 3-to-2 adapter into the TB daisy-chaining port of the Thunderbolt Display.

The Mac Mini M4 has no issues with the Apple TB display. I have it connected to my Mac Mini M4 pro and no issues using the Apple TB3 to TB2 adapter.