Carbon Copy Cloned drive not booting 2020 16 inch 5600m mbp

[applesed]

I have an external seagate hd was cloned off an early 2020 5500m 16 inch mbp, that boots fine when I try to boot from a distinct but similar timeframe and configuration 2020 5500m 16 inch mbp, but when I try to boot from it on a 5600m 16 inch mbp, I get the crossed out, no access screen. I’ve tried multiple bootable clones, seagate, Wd, different usbc hubs, ports, and same results.

is there something inherently different in terms of firmware, or hardware or anything else? What could be causing this incompatibility? I’m able to boot a 2013 mini with each of these drives.

 

[Xgx]

Apologies if this is obvious, but have you enabled booting from external media on the target computer? I believe this option is off by default https://support.apple.com/en-gb/HT208198

 

[applesed]

Right that was the very first step, allow from external boot is the current setting.

 

[applesed]

App forum? Not sure this isn't more tied to hardware based on the experiment described.

 

[chrfr]

I have an external seagate hd was cloned off an early 2020 5500m 16 inch mbp, that boots fine when I try to boot from a distinct but similar timeframe and configuration 2020 5500m 16 inch mbp, but when I try to boot from it on a 5600m 16 inch mbp, I get the crossed out, no access screen. I’ve tried multiple bootable clones, seagate, Wd, different usbc hubs, ports, and same results.

is there something inherently different in terms of firmware, or hardware or anything else? What could be causing this incompatibility? I’m able to boot a 2013 mini with each of these drives.

The MBP with the 5600 needs a specific build of Catalina 10.15.5 or later. If your cloned drive is updated to 10.15.6, this should not be a problem anymore.

 

[applesed]

I actually did this, this morning before i saw your post. I updated to the latest Catalina and recloned (incremental update of clone with full version). Now it is not showing the cross-out, it shows the apple icon loading, and then I get a grey screen. And it stops with the grey screen. I tried again, and it eventually filled out the grey screen "A software updated is required to use this startup disk". I click "Update", and it says updated failed immediately. Why is it asking me to perform the update when the clone already has it..

edit: I entered my wifi information and looks like it's updating now.

edit2: "Your computer restarted because of a problem" message during the update.

another update: I gave up on trying to update it from that screen, booted into the native drive OS, downloaded the update, and it's crashing with edit2 error above. sub "another update" : looks like it started it even with that error, "x minutes remaining" I take is a good sign.

 

[chrfr]

I tried again, and it eventually filled out the grey screen "A software updated is required to use this startup disk". I click "Update", and it says updated failed immediately. Why is it asking me to perform the update when the clone already has it..

This is because when you updated the disk on another computer, and then brought it over to the 16”, the firmware on the T2 chip in the 16” is out of date and needs to update.

 

[applesed]

This is because when you updated the disk on another computer, and then brought it over to the 16”, the firmware on the T2 chip in the 16” is out of date and needs to update.

Yea it occurred to me it wasn't just an OS update. I eventually got the update to take on the new machine after of couple of those "something went wrong errors", but then couldn't get it to boot off the drive using Option and selecting the drive, it would just go to the onboard disk.

I then tried Cmd+R, selecting it in that GUI, and looks like it is finally loading the bootable OS. Based on that last sequence I'm wondering if I might be in a lemon situation. It's loading the OS slowly but will see if I can get this clone onto the new machine started. It is loading extremely slow which I come to expect when booting off an external drive but not this slow.

 

[applesed]

I managed to start the clone, stepped away, and looks like it froze.

I'm going to try this process again from the beginning with a seagate external, which I have always had success with. I just happened to use a WD on the current time through, maybe that is the difference, and this is a problem separate form the firmware update that I seemed to have solved.

 

[applesed]

after switching to seagate and repeating steps and letting the clone on new system to run overnight, it finally finished and boot. thanks for your input chrfr.