Thunderbolt 2 to Thunderbolt 4 will not connect apple monitor to Studio Mac

If it is a 27" LED Cinema Display, it definitely won't work when plugged into the adapter.

That adapter only translates Thunderbolt. If your old Mac had a Thunderbolt 1 or 2 port, it would react to plugging in a non-Thunderbolt device by presenting a DisplayPort signal on the connector. I believe that other Thunderbolt 1 and 2 devices would also know how to do this if they detected that they were the last TB device on a TB chain.

The adapter does not know how to do that.

Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter - Apple

"Note: This adapter does not support DisplayPort displays like the Apple LED Cinema Display or third-party DisplayPort and Mini DisplayPort displays."

What you're looking for is a USB-C to Mini DIsplayPort adapter or adapter cable. (The descriptions may refer to Thunderbolt, but the adapters really rely on DisplayPort Alt Mode, not on Thunderbolt at all.)

https://www.amazon.com/s?k=usb-c+to+mini+displayport+adapter

https://www.amazon.com/s?k=usb-c+to+mini+displayport+cable

are you using one of the Mac Studio's Back ports to make the connection? The Front ports on the Max (not Ultra) are not ThunderBolt-capable and are speed limited.

The Mac uses a system that reminds me of “Plug and play” to determine what display is connected, and what its capabilities are.

To get a Mac display to become active, you need the Mac to query the display, and the display to answer with its name and capabilities. Otherwise, the display will not be shown as present, and no data will be sent to the display. "No signal detected" is generated by the DISPLAY, not by the Mac.

This query is only sent at certain times:

• at startup

• at wake from sleep — so momentarily sleeping and waking your Mac may work

• at insertion of the Mac-end of the display-cable, provided everything on that cable is ready-to-go

• hold the Option key while you click on the (Detect Display) button that will appear in Displays preferences (from another display)

so try doing some of those things and see if the display comes alive.

Genefromconcord wrote:

27" display. MagSafe and Thunderbolt 2 (square) connector. No USB. Will not connect to Mac Studio with the T2 to T3 dongle.

Thunderbolt 1 & 2 have the same connector as Mini DisplayPort, so the shape of the connector won't tell you if you have a 27" Thunderbolt Display or a 27" LED Cinema Display.

Both of these displays have MagSafe connectors and downstream USB 2.0 ports. The 27" Apple Thunderbolt Display has a Firewire 800 port that is not present on the 27" LED Cinema Display.

If this display worked with a MacBook without a TB3-to-2 adapter, and won't work with a M2 Mac mini with one, I'm thinking it is probably a 27" LED Cinema Display. If it was that, both Mini DisplayPort and Thunderbolt 1 or 2 cables would have supported a Mini DisplayPort connection.

The 27" Apple Thunderbolt Display has model number A1407, and requires Thunderbolt input.

The 27" Apple LED Cinema Display has model number A1316, and requires Mini DisplayPort input.

The Apple TB3-to-2 adapter is the right one to use IF you need a Thunderbolt connection, and the WRONG one to use IF you need a Mini DisplayPort one. It only translates Thunderbolt and does not have the ability to offer a plain DisplayPort signal on the TB2 side when that would be appropriate.

For connecting the 27" LED Cinema Display, you would want a USB-C (DP) to Mini DIsplayPort adapter cable, and probably also a USB connection, so the computer can operate the software-controlled features of the monitor.

WHICH Apple monitor?

is it a 27-in diagonal?

does it have a model number?

how many connectors of what type the in the lead-in cord? { MagSafe and Thunderbolt-2 AND USB, or NO USB?}