MacOS Passcode lock

[Asnyder]

I've use the lock device management command on a MacBook air (2015). The student tried the get in several times and now it's stuck at the "wrong passcode try again" screen with nowhere to enter the code. I've tried rebooting but it just gives me a 60 minute cooldown time and then the same "wrong passcode" screen. Any Ideas to get this unlocked?

[crbeck]

Send the "Lock Computer" command again, it'll reboot and you'll be able to put in the passcode (this would be the most recent passcode you just set). It should reboot after you put in the passcode and ask for the passcode again (this would be the original passcode you set). Put it in and then it should unlock and be good.

That's been the process I've had to use on a couple machines, pulled from this Jamf Nation post.

[Eyoung]

I have has repeated issues with locking. same thing you describe, infinite 60 minute loop. In my case it looked to be caused by the student with the locked machine face-rolling the keyboard in anger until it just sorta seizes up. I was not successful resending the lock command.

I ended up having to take the effected laptops to the Apple store for some super secret unlocking ritual (bring a chicken, a sharp stone and some Gatorade).... i've had three lock up this way on me thus far.

[Asnyder]

I haven't had any luck getting the field to pop back up, or locking the device again. Shortly after posting this I did notice that it must be setting an EFI password - the one you sent to the device - and I was able to netboot. I bet if you boot to a netinstall and run the EFI tool to remove the password it will unlock it. Haven't tested yet though.

[ronhun1]

Im wondering if removing the MDM profile would it just unlock?

[ageevarughese]

I've had this happen to me in the past for my organization. Entering in the wrong code after 3 or 4 attempts will result in this infinite 60 min loop where the right code will not work anymore. You will have to contact Apple at this point as the computer is now completely locked as the lock command also locks the EFI. They will have to verify the purchase date by using the serial number provided. Once verified they will provide instructions on how to unlock the device, which consists of using a key command at the EFI lock stage that will display a code. Once they have that code they will send you a file to download/install onto a thumb drive to which can be used to unlock the computer.