MP 1,1-5,1 MP 5.1 and Apple Locked from Hell

[Djulz2]

Hello, all. I have a MP 5.1 running on 10.14 with a RX580 (unflashed), I updated the procs to 3.46, 12 cores, things were running smoothly, there is no filevault or encrypted DD. I traveled along with my 2 kids and left my pregnant wife home (she cannot travel)and decided to lock my mac from another device in order that she doesn't use my main computer (its my only desktop left)while im away. Locked it from icloud, (marked as lost). I returned yesterday to have the displeasure of finding the computer running with black screen, she said she just powered it once and that it was like that, she saw no prompt... I restarted, nothing just black screen, no prompt for password or unlock. I checked on that idevice 'find my mac' (iPhone etc) and the Macpro appears with a locked icon but no ability to unlock it from there. When clicking on the 'Mark as lost' icon I get the possibility to lock the mac (again!!!) but not unlock it. I did lock the Macpro 2 months ago and there was no issue, I was prompted with password input, now nothing, just the mac chime after 1 minute, and blank screen. Im very worried because since my graphic card is non flashed PC card, it works but I have no bootscreen progression, Im not even sure I can use the recover mode because I won't see anything. I tried the Pram reset but it does not work only the mouse is lit (gaming mouse with leds)!! Has it ever happened to anyone, any clue?
Thank you
PS :I have my Icloud password and I see the machine listed but no clue how to unlock it
PS2 : since it does not (apparently) boot normally, maybe its locked but cannot access to internet and therefore creates the problem?
PS: there is an option to erase the machine, maybe I could put another HD and proceed and then put a old hd back ?
Does this erase procedure affect anything else?

 

[hg.wells]

In your screenshot, what happens when you tap on the activated section under Mark as Lost? The section that says "Activated 18th December"

 

[Djulz2]

In your screenshot, what happens when you tap on the activated section under Mark as Lost? The section that says "Activated 18th December"

It says "Lock this mac" but im quite certain I already locked it!

 

[Freeangel1]

Have you seen this?

Have you followed any of the steps to deactivate LOST mode?

How to Unlock MacBook in Lost Mode

Unlock MacBook Pro that stuck in Lost Mode with enabled System Lock PIN

iremove.tools

After you locate your Mac, you can unlock it by entering the passcode that you created when you locked it with Find My. If you can't remember that passcode, you have three options: Sign in to iCloud.com/find, then select your Mac from the Devices menu. Select Unlock and follow the steps to verify your identity.

 

[MarkC426]

Seems a bit extreme to mark a Mac, which is at home, as lost.
I think you where asking for trouble, as it is probably locked for security.

Could you have not just asked your wife to not use your Mac...?

Try the solution @Freeangel1 suggested.

 

[Djulz2]

Have you seen this?

Have you followed any of the steps to deactivate LOST mode?

How to Unlock MacBook in Lost Mode

Unlock MacBook Pro that stuck in Lost Mode with enabled System Lock PIN

iremove.tools

After you locate your Mac, you can unlock it by entering the passcode that you created when you locked it with Find My. If you can't remember that passcode, you have three options: Sign in to iCloud.com/find, then select your Mac from the Devices menu. Select Unlock and follow the steps to verify your identity.

There is a discrepancy
It’s appears as locked since 24th of December, the day she probably opened it, and
I have 3 options from the drop down menu :
-Register as lost
-Erase device
-Remove device
No password input on either my M1 MacBook or iPhone!!!!
It’s a nightmare.

 

[Djulz2]

Have you seen this?

Have you followed any of the steps to deactivate LOST mode?

How to Unlock MacBook in Lost Mode

Unlock MacBook Pro that stuck in Lost Mode with enabled System Lock PIN

iremove.tools

After you locate your Mac, you can unlock it by entering the passcode that you created when you locked it with Find My. If you can't remember that passcode, you have three options: Sign in to iCloud.com/find, then select your Mac from the Devices menu. Select Unlock and follow the steps to verify your identity.

I’m in front of all my apple devices (MacBook pro M1, iPhone ) it’s listed but there’s no option to unlock it. Mac Pro starts, 25 to 30 seconds wait, then chime, then nothing, no signal to the screen, no input challenge to password… that’s the issue!
I have my password and code to unlock, just it’s nowhere to be entered.

 

[hg.wells]

I’m in front of all my apple devices (MacBook pro M1, iPhone ) it’s listed but there’s no option to unlock it. Mac Pro starts, 25 to 30 seconds wait, then chime, then nothing, no signal to the screen, no input challenge to password… that’s the issue!
I have my password and code to unlock, just it’s nowhere to be entered.

Could you power up the machine and then try typing it in and hitting enter, I wonder if it’s just the graphics card.

 

[hg.wells]

I’m in front of all my apple devices (MacBook pro M1, iPhone ) it’s listed but there’s no option to unlock it. Mac Pro starts, 25 to 30 seconds wait, then chime, then nothing, no signal to the screen, no input challenge to password… that’s the issue!
I have my password and code to unlock, just it’s nowhere to be entered.

Could you power up the machine and then try typing it in and hitting enter, I wonder if it’s just the graphics card

 

[MarkC426]

Is this the same technique here:

If your Mac is lost or stolen - Apple Support

If your Mac goes missing, these steps might help you find it and protect your information.

support.apple.com

 

[Djulz2]

Could you power up the machine and then try typing it in and hitting enter, I wonder if it’s just the graphics card

Good question, it looks like my keyboard is not even responding when I press capslock, it does not turn light up, but the led mouse does! I did compose the code even if the screen is black and nothing happens!!!! It was fully working with no issue before I left.

 

[Djulz2]

Ok Gang! The issue came from the graphic card, its not flashed and therefore you don't know what is going onscreen, after finding an old card 5770 I plugged it out of dispair and Ta-dah, I got bootscreen and two different times to input password, last when I saw the option to unlock the mac on my other devices! If you don't have a spare GC, you could be out of luck! What I don't understand is why and how it worked the first time, two months ago... probably one of my wife's trick!
Thanks to all of you who helped and the rest of you out there, hope its of use for MP users!