Hello,
I tried to connect my brand new MacBook Pro 14" M1 Max to my good old Apple Thunderbolt Display via my Apple Thunderbolt 1/2 to Thunderbolt 3 adapter, and... nothing happened. The MacBook Pro doesn't recognize the display.
However, the display and its adapter are working perfectly fine with a MacBook Air (2018).
Is there a problem of retro compatibility of Thunderbolt 4 with Thunderbolt 1/2?
MacBook Pro 14″, macOS 12.0
Ok, so, there is a solution to the problem. A weird one but still a solution.
I found a Mac mini M1 owner that also struggled to connect its Apple Thunderbolt Display.
First, you need to acknowledge that the Thunderbolt port on the back of the display can also be used as an input. (Yeah, big surprise to me too!)
Then, you just use that port with a Thunderbolt 1/2 cable (and of course, the Adapter Thunderbolt 3 (USB-C) to Thunderbolt 1/2) and it just works.
It shouldn't behave like this at all, there must be a glitch somewhere in all that retro-compatibility Thunderbolt/USB-C mess, but that's how I troubleshoot it.
Ok, so, there is a solution to the problem. A weird one but still a solution.
I found a Mac mini M1 owner that also struggled to connect its Apple Thunderbolt Display.
First, you need to acknowledge that the Thunderbolt port on the back of the display can also be used as an input. (Yeah, big surprise to me too!)
Then, you just use that port with a Thunderbolt 1/2 cable (and of course, the Adapter Thunderbolt 3 (USB-C) to Thunderbolt 1/2) and it just works.
It shouldn't behave like this at all, there must be a glitch somewhere in all that retro-compatibility Thunderbolt/USB-C mess, but that's how I troubleshoot it.
No, I haven't.
I tried the most simple configuration: only the macbook pro (powered by its MagSafe), the Apple Thunderbolt adapter and the Apple Thunderbolt Didplay. And I tried it on all three of the MacBook Pro's Thunderbolt ports.
Nothing is happening
My problem isn't solved at all but I tested the MacBook Pro's Thunderbolt 4 port a bit more:
I connected an old external Thunderbolt (1, I think) LaCie Rugged SSD with the Apple Adapter Thunderbolt 3 (USB-C) to Thunderbolt 1/2 and... it mounted correctly!
Well, I had to do it twice to get proper speeds of read and write but it worked.
So the Thunderbolt 4 ports can recognize Thunderbolt 1 devices through the Apple Thunderbolt adapter.
And disks protocol is recognized but not displays protocol?
Please, tell me it is just a matter of firmware upgrade...
Do you have another display connected to the other Thunderbolt port on the computer?
MacBook Pro 14" M1 Max can't connect with Apple Thunderbolt Display
