How to block FMM on macbook pro?

[lovecd]

Got a macbook pro 16" 2019 model from local market place, however, found it has FMM linkage during reset process, and unable to get response from the seller anymore. So, for this FMM issue, will that be safe if I didn't turn on location service? Or is there any trick solution I can apply in order to use it for regular daily work?

Many thanks.

 

[B S Magnet]

Shy of physically removing the EFI chip and installing (soldering, then configuring) an unused, blank one, or sourcing a completely different logic board, there is probably nothing you can do. Your seller may have sold you a lifted unit, leaving you stuck with the outcome.

 

[lovecd]

Shy of physically removing the EFI chip and installing (soldering, then configuring) an unused, blank one, or sourcing a completely different logic board, there is probably nothing you can do. Your seller may have sold you a lifted unit, leaving you stuck with the outcome.

Just curious to ask, should FMM work based on location service? If I didn’t turn on location on this laptop, the other end (who set it up initially) can not do anything on this computer, right?

 

[Sheepish-Lord]

It doesn’t have anything to do with location services so yes it’s still being tracked regardless. As far as the person, they can lock the machine and erase it remotely.

Still hard to believe people buying used Apple products these days don’t check the ONE thing that literally makes the device useless or not.

 

[B S Magnet]

Just curious to ask, should FMM work based on location service? If I didn’t turn on location on this laptop, the other end (who set it up initially) can not do anything on this computer, right?

My experience with FMM, specifically, is limited to iOS devices like the iPhone and iPad (the closest analogue with Macs I’ve used is the older, third-party utility, Undercover, which functions in a fundamentally different way).

From what I understand, Find My Mac (or just “Find My”) is set up beforehand by the person who activated it, via their iCloud account. This means it’s linked, via EFI chip-level, to the account of the user who set it up. Location service is irrelevant here so much as a cryptographic key which was set and saved to EFI, when Find My was set up and activated. The key set on the EFI is expecting to be unlocked by its cryptographically matched originator of the key (that is: the person’s whose iCloud account set up Find My activation originally). Only that match can unlock it and, if they desired, un-pair the device from their iCloud account.

The step by step overview is expanded upon with this page.

 

[B S Magnet]

It doesn’t have anything to do with location services so yes it’s still being tracked regardless. As far as the person, they can lock the machine and erase it remotely.

Still hard to believe people buying used Apple products these days don’t check the ONE thing that literally makes the device useless or not.

From a buyer’s vantage, what method (beyond the honour system of a seller’s word) should one exercise in due diligence to assure a used Mac is being sold to you in good faith?

I ask this as a longtime user of older, used Macs (i.e., pre-Touchbar/T2 era) whose provenances have always been clear (for me) from the outset, but when dealing with buying a used Mac online (such as that electronic auction service in the sky), what (beyond a photo by the seller showing the “Hello” screen, which may or may not be a kosher indicator) should a buyer be looking for?

Cheers.

 

[lovecd]

My experience with FMM, specifically, is limited to iOS devices like the iPhone and iPad (the closest analogue with Macs I’ve used is the older, third-party utility, Undercover, which functions in a fundamentally different way).

From what I understand, Find My Mac (or just “Find My”) is set up beforehand by the person who activated it, via their iCloud account. This means it’s linked, via EFI chip-level, to the account of the user who set it up. Location service is irrelevant here so much as a cryptographic key which was set and saved to EFI, when Find My was set up and activated. The key set on the EFI is expecting to be unlocked by its cryptographically matched originator of the key (that is: the person’s whose iCloud account set up Find My activation originally). Only that match can unlock it and, if they desired, un-pair the device from their iCloud account.

The step by step overview is expanded upon with this page.

Thanks for this detailed explanation! And by the way, is there a way (except machine reset) to check if it has FMM lock on it?

 

[rpmurray]

Even with location services turned off, Apple will still know if you're on-line or not. In that case the Apple ID account that set up FMM will be able to lock or wipe it whenever they choose.

Edit: Took too long to respond. Other commenters got here while I was still fumbling with my keyboard.

 

[B S Magnet]

Thanks for this detailed explanation! And by the way, is there a way (except machine reset) to check if it has FMM lock on it?

I don’t know the answer to that. @Sheepish-Lord might know, though.

 

[rpmurray]

Thanks for this detailed explanation! And by the way, is there a way (except machine reset) to check if it has FMM lock on it?

If it's a T2 Mac, you can open the System Report and in the Hardware Overview section it will indicate if Activation Lock Status is enabled or not. Activation Lock is enabled when you activate FMM.

Also Find My Mac already in use (on a bought Mac) covers OPs situation. There's a line that indicates that if the Find My Mac setting shows "Find My Mac already in use" and you click on it you should see the Apple ID email address, so OP may be able to get in touch with the previous owner that way and ask them to disable FMM for that device.

 

[Slartibart]

as long as they are not locked down there is a way to deal with this on iDevices. For macOS there is none AFAIK.

 

[lovecd]

If it's a T2 Mac, you can open the System Report and in the Hardware Overview section it will indicate if Activation Lock Status is enabled or not. Activation Lock is enabled when you activate FMM.

Also Find My Mac already in use (on a bought Mac) covers OPs situation. There's a line that indicates that if the Find My Mac setting shows "Find My Mac already in use" and you click on it you should see the Apple ID email address, so OP may be able to get in touch with the previous owner that way and ask them to disable FMM for that device.

Thanks!

 

[MallardDuck]

Definite don’t use it with it enable though, too big a risk.

 

[lovecd]

If it's a T2 Mac, you can open the System Report and in the Hardware Overview section it will indicate if Activation Lock Status is enabled or not. Activation Lock is enabled when you activate FMM.

Also Find My Mac already in use (on a bought Mac) covers OPs situation. There's a line that indicates that if the Find My Mac setting shows "Find My Mac already in use" and you click on it you should see the Apple ID email address, so OP may be able to get in touch with the previous owner that way and ask them to disable FMM for that device.

I just checked the "hardware overview" section and found the activation lock is currently disabled, and check back "find my Mac" under internet account, but didn't find anything shows up under internet account, does it mean I'm safe now or did I check the wrong place? The current OS installed is Ventura 13.4.1. Any thoughts?

Thanks,

 

[Slartibart]

Can you add the Mac in FMM under your Apple ID? And while we’re at it: is there maybe a profile under System Settings>Privacy and Security?

 

[Yebubbleman]

Got a macbook pro 16" 2019 model from local market place, however, found it has FMM linkage during reset process, and unable to get response from the seller anymore. So, for this FMM issue, will that be safe if I didn't turn on location service? Or is there any trick solution I can apply in order to use it for regular daily work?

Many thanks.

Having Find My Mac still turned on is a big problem. Yes, you can wipe it and have it not be tracked, but you will be unable to get even out-of-warranty service done on that Mac should anything have issues. Furthermore, if bridgeOS on the T2 chip is restored, you will be prompted for Activation Lock which will still be registered to the previous user.

You can wipe the OS which will allow the Mac to be usable, but this is still far from ideal. Were it me, I'd try to sell it and cut your losses. The person you bought this from did you dirty.

Shy of physically removing the EFI chip and installing (soldering, then configuring) an unused, blank one, or sourcing a completely different logic board, there is probably nothing you can do. Your seller may have sold you a lifted unit, leaving you stuck with the outcome.

You'd need to source a different logic board. And it's the T2 chip that actually controls Activation Lock.

 

[Fishrrman]

(sigh)
Another "great deal" on a [stolen] Mac...

 

[lovecd]

Can you add the Mac in FMM under your Apple ID? And while we’re at it: is there maybe a profile under System Settings>Privacy and Security?

Just tried adding the Mac in FMM under my Apple ID, I can add my Apple ID to this Mac without any problem, and all the way to last step until it prompts: "Enabling Find My Mac will disable it from "xxxx". Find My Mac can only be used by one user at a time, cancel or continue, while "xxxx" I believe is the previous owner.

So, my questions here is, if I click the "continue" button, will it disable the previous user "xxxx" and I will have the ownership instead, or it will just disable and lock this Mac right away? Any thoughts?

Thanks,

 

[kitKAC]

The prompt is telling you exactly what's going to happen, press continue. If there was a chance of disabling the machine, macOS wouldn't let you try to switch on Find My Mac at all.

There's a thread on here somewhere from someone who tried to add Find My Mac to every account they one on their Mac and was wondering why it kept signing out Find My... from the other accounts (or something like that).

 

[lovecd]

The prompt is telling you exactly what's going to happen, press continue. If there was a chance of disabling the machine, macOS wouldn't let you try to switch on Find My Mac at all.

There's a thread on here somewhere from someone who tried to add Find My Mac to every account they one on their Mac and was wondering why it kept signing out Find My... from the other accounts (or something like that).

OK, will try that continue button tonight and let you know the update. Thanks.

 

[lovecd]

The prompt is telling you exactly what's going to happen, press continue. If there was a chance of disabling the machine, macOS wouldn't let you try to switch on Find My Mac at all.

There's a thread on here somewhere from someone who tried to add Find My Mac to every account they one on their Mac and was wondering why it kept signing out Find My... from the other accounts (or something like that).

Here is the update, finished that process by hitting continue button, now "iCloud" under "Find My Mac" shows my account, does it mean it has disconnected from the previous owner and I'm safe to use it now? Just curious, if the new user can use this way to unlink the old owner, what's the point to have this FMM feature implemented?