Using external monitor (A1407) with my MacBook Air (2020) running Sonoma.

A1407 is an Apple Thunderbolt Display. You cannot use USB-C to Mini DisplayPort adapters. They may have connectors that fit, but they carry the wrong type of signal. You need the Apple Thunderbolt 3-to-2 adapter.

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

Ozcar_Photograper wrote:

Hi, I bought the adaptor directly from apple but still the monitor does not respond, any advice?, I'm using a Mac Book Pro 13-inch with a A1407 Apple Thunderbolt Display.

Check that this is an A1407 (Apple Thunderbolt Display – has a FireWire 800 port, and no USB uplink), and not a similar A1316 (27" LED Cinema Display – has a USB uplink, but no FireWire 800 port).

• A1407 - Will work when connected via TB3-to-2 adapter, but NOT when connected via a USB-C to mDP one. (A USB-C to mDP adapter will not provide a Thunderbolt signal.)
• A1316 – Will work when connected via USB-C to mDP adapter, but NOT when directly plugged into TB3-to-2 one. (That adapter does not know how to make the TB2 side appear to be a plain Mini DisplayPort.)

If it is an A1407 Apple Thunderbolt Display, and things aren't working, the permanently-connected "hydra cable" may be bad. You could try running a Thunderbolt 1/2 cable from the TB3-to-2 adapter to the TB daisy-chaining port on the display to bypass the bad cable.

I’m using 2021 MacBook Pro with the monitor using usb to thunderbolt adaptor. Works fine. However you can’t charge you air with the power cable.

Sorry just to clarify this is exactly what I use.

If your Mac has a Thunderbolt 3 or 4 port (with a USB-C connector), you can connect a 27” Apple Thunderbolt Display (model A1407) with the aid of an Apple Thunderbolt 3-to-2 adapter.

There is no adapter that will let you connect that display to a USB-A port, or to the USB-C ports on 12” Retina MacBooks (which have USB-C but lack Thunderbolt). The display only works with a Thunderbolt signal.

Hi, I bought the adaptor directly from apple but still the monitor does not respond, any advice?, I'm using a Mac Book Pro 13-inch with a A1407 Apple Thunderbolt Display.

I try to force the Mac to identify the Display by pressing the Key Option in System Settings>Displays but the Mac can't "see" the A1407 Apple Thunderbolt Display.

The AC conector is well connected

Oscar

This is what I'm trying to do! Do you have an adapter that converts the display's thunderbolt cable to USB (female to male) for your MacBook? I tried Apple support chat and they couldn't tell me.