Target Disk Mode Macbook Air to Neo - which cable

To fulfill you original request to use the MacBook Neo and Target Disk with  the Intel 2019 MBA

Unfortunately, the MacBook Neo's lack of Thunderbolt does prevent you from using Target Disk Mode directly between these two Macs.

The confusing part is that USB-C describes the physical connector, not the technology being used through it. Your 2019 MacBook Air has Thunderbolt 3 ports, while the MacBook Neo's USB-C ports support USB 3 and USB 2 but not Thunderbolt.

This also explains the message you received. The USB-C charging cable itself does not have to be a Thunderbolt cable for the Neo to display a Thunderbolt compatibility warning. Apple says that devices which use only Thunderbolt aren't compatible with the Neo, and that an alert appears when such a device is connected. (Apple Support)

More importantly, Apple's current Target Disk Mode instructions state that when either Mac is running macOS 11 or later, the two Macs must be connected using Thunderbolt. (Apple Support) In other words, the problem isn't the particular USB-C cable you tried; it is that the connection required by Target Disk Mode cannot be provided by the Neo.

Unfortunately, a different USB-C cable, a Thunderbolt cable, or a USB-C-to-Thunderbolt adapter won't overcome this limitation. The Neo doesn't contain Thunderbolt hardware, and an adapter cannot add Thunderbolt capability to it.

I therefore wouldn't buy a Thunderbolt cable specifically to connect the Air to the Neo. Instead, if the files are important, I would try to get access to another Mac with a Thunderbolt port. You can then start the 2019 Air in Target Disk Mode by holding T while starting it and connect it to that Mac with a Thunderbolt cable. If the Air's internal storage is still functioning, it should appear as an external disk so the files can be copied. (Apple Support)

The fact that the Air still produces the startup chime is encouraging, although it doesn't establish that the internal storage is healthy. Since both the built-in display and the HDMI display are blank, there may be a hardware problem beyond the display itself.

For reference, Apple's relevant documentation is Target Disk Mode, which specifies the Thunderbolt requirement, and MacBook Neo: Connect accessories, which explains the Neo's Thunderbolt incompatibility. (Apple Support)

Since your 2019 MacBook Air makes the startup sound but the screen stays blank, including on an external monitor, I’d start with the basic Apple troubleshooting steps. Hold the power button for up to 10 seconds to shut it down, disconnect any non-essential accessories, and try starting it again. Apple Support: If your Mac starts up to a blank screen

If the screen remains blank, try macOS Recovery by turning on the Intel-based Mac and immediately holding Command (⌘)-R. If Recovery appears, Disk Utility can be used to check or repair the startup disk, and macOS can be reinstalled if necessary. If the files are important and you do not have a current backup, I would avoid erasing or reinstalling macOS until you have considered your data-recovery options. Apple Support: If your Mac starts up to a blank screen

You can also try Safe Mode by holding Shift during startup. Apple describes Safe Mode as a way to help determine whether software that loads during startup is contributing to the problem. Apple Support: Use Safe Mode on your Mac

If Recovery does not start, the 2019 MacBook Air has Apple's T2 Security Chip, and Apple provides a firmware-recovery procedure for these Macs. A revive does not erase the Mac, while a restore does. A revive is therefore the appropriate firmware option to consider before a restore when preserving the data matters. The procedure requires another compatible Mac and a suitable USB-C cable. Apple Support: How to revive or restore Mac firmware

You can also run Apple Diagnostics by starting the Intel-based Mac while holding D. Apple Support: Use Apple Diagnostics to test your Mac

You therefore may not need to use the MacBook Neo or Target Disk Mode as the first step. However, if the Mac remains inaccessible and the primary goal is recovering its files, Target Disk Mode or another data-recovery approach may still be appropriate. Its usefulness cannot be assumed solely from the startup chime. I would avoid a firmware restore or erasing the Mac until the data has been backed up or you have decided how you want to proceed with recovery.

If the Mac cannot start Recovery or be revived, Apple indicates that it may need service. Apple Support: If your Mac starts up to a blank screen

Elde_ wrote:

Can I buy any cable that says “Thunderbolt” or are there differences? The prices seem to vary enormously.

Be aware that

• Thunderbolt 1 and 2 use Mini DisplayPort connectors
• Thunderbolt 3, 4, and 5 use USB-C connectors
• Thunderbolt 4 and 5 are not backwards-compatible with Thunderbolt 1 and 2, even with the use of an adapter such as the Apple Thunderbolt 3-to-2 one.

Since your 2019 MacBook Air has Thunderbolt 3 ports, you will probably be dealing with Thunderbolt 3 cables or Thunderbolt 4 cables - but if you were talking about an older computer with Thunderbolt 1 or 2 ports, then things could get real "conditional" and real expensive really quickly.

FYI, it appears that your 2019 MacBook Air is recent enough that the SSD is soldered in and that its contents are encrypted (Mac computers with the Apple T2 Security Chip - Apple Support). So pulling the drive out of the Mac and putting it into a USB enclosure, or another old Mac, would not be an option if you cannot revive the machine enough to start up macOS or to put the machine into Target Disk Mode.

Thank you, this is really helpful. The Air has in fact stopped making the start-up noise (the screen lights up to a blank dark screen and that’s all). The problem started last week when the screen suddenly went dark but the sound continued to play. I shut it down then restarted it after several attempts, it was then fine but the exact same thing happened 30 minutes later after which I was unable to turn it on again. It was still making the start-up chime the following day when I tried (and I could hear the fan going) but this has now stopped for good too which I assume is not a good sign.

I did try the different recovery / safe modes but with no results. My partner suggested the graphics card may be cooked because the HDMI monitor displayed the exact same blank screen when connected.

Unfortunately the files were not backed up, I had my important documents saved elsewhere but I'd like to get access to and copy the rest mostly for sentimental and practical reasons. Expensive lesson learned!

Thank you for the clarification about cables and ports, that makes sense and it was exactly what I was confused about. I will try to get access to a different Mac and use Target Disk Mode with a Thunderbolt cable. Can I buy any cable that says “Thunderbolt” or are there differences? The prices seem to vary enormously.

You are welcome

Given what you have described, I think recovering your files should be the priority. 

The fact that the external monitor showed the same blank screen makes a display or graphics problem possible, but it does not  tell us that the graphics hardware has actually failed. Likewise, the loss of the startup chime does not  identify the failed component.

Before buying a cable, the important thing is to establish your MacBook Air has an Intel processor . 

An Intel Mac can use Target Disk Mode, whereas an Apple-silicon Mac uses Share Disk through macOS Recovery. 

Apple explains both procedures here: Transfer files between two Mac computers using Target Disk Mode and Use macOS Recovery on a Mac with Apple silicon.

If yours uses Target Disk Mode, you will want a genuine Thunderbolt 3 or Thunderbolt 4 cable. 

Although the connector looks like USB-C, not every USB-C cable supports Thunderbolt. 

Apple notes that Thunderbolt 3 supports data transfer speeds of up to 40 Gbps. (Apple: About the Apple Thunderbolt 3 Pro Cable) There’s no particular reason to pay a large premium for one brand over another.

If the Air’s storage is encrypted, you may also need the MacBook Air’s login password or other credentials before the files can be accessed. 

Until you have recovered what you want, I would avoid erasing or initializing the drive, or reinstalling macOS.

Thank you!

Yes, the 2019 Macbook Air has an Intel processor.

I do not think the storage was encrypted.

Thank you for this. Yes, I will get a Thunderbolt 3 or 4 cable. Is there any difference?

Elde_ wrote:

Thank you for this. Yes, I will get a Thunderbolt 3 or 4 cable. Is there any difference?

If your time permits, keep us posted on your computer progress 🤞

🦉-53

I will, thank you for your help!