Issues connecting Thunderbolt Display 27” to Mac mini M4

Question

Level 1

4 points

Issues connecting Thunderbolt Display 27” to Mac mini M4

Hello,

I am having issues connecting my Thunderbolt Display 27” to my Mac mini M4. To connect, I use the original Thunderbolt 2 to Thunderbolt 3 adapter. The monitor worked successfully with the Mac mini for some time, but then it stopped connecting or failed to display an image after the computer woke up from sleep.

The only way I was able to get an image was by unplugging the Mac mini from power and turning it back on. However, about 30 seconds after startup, the image would disappear again.

I downgraded from macOS Tahoe to macOS Sequoia 15.7, and the monitor worked perfectly for one day, but then the problems returned.

I have tested the monitor with my MacBook Pro 2015, and it works fine. I also tested the adapter, and it is working correctly.

What could be the problem, and how can I fix it?

Mac mini, macOS 15.7

Posted on Sep 26, 2025 3:47 AM

Reply

Answer 1

Top-ranking reply

Servant of Cats

Level 7

31,463 points

Sep 26, 2025 4:05 AM in response to nopenop

Modern versions of macOS are intolerant of display transmission errors – as in, they don't want to see any, and will cut resolution or signal if they do.

The permanently-attached "hydra" cables on those old Thunderbolt Displays are often a bit flaky.

Some people report success running a Thunderbolt 1/2 cable from the Apple Thunderbolt 3-to-2 adapter to the Thunderbolt daisy-chaining port on the Thunderbolt Display, leaving the permanently-attached cable unused.

Reply

Answer 2

Sep 27, 2025 4:56 AM in response to Servant of Cats

+1

And to add I have used a TB 1/2 cable to the daisy-chain port with my own 27" TB display and it works just fine for years since the "octopus" cable went flakey.

Reply