<< Solved >> Suddenly Black screen after apple logo on system running almost 3 yrs

[Middleman]

After some more hours fiddling around, I was able to get the drive to boot with my old Mojave install stick. I am not sure what exactly happened but I guess my EFI partition or files there-in got corrupted somehow. I ran diskutil repairVolume on both the Macintosh HD part and the EFI part and neither came up with errors.

I ended up re-running Multibeast, following the instructions from the GA-Z390 Designare post and put my original custom SSDT and now it boots again from the HD. Yay!

The recovery was touch-and-go for a bit, because of the certificate expiration on the old Multibeast 11.3 for Mojave. Setting the clock back to 2019 worked, but the install took 40+ minutes to complete, I can only imagine it was hitting some 2-3 minute web timeout for every install step due to the non-functional internet because of the time-clock difference.

What I am not understanding is why the subsequent post-install Clover Configurator setup steps didn't complete according to the guide (I switched the time back to present before running configurator). Particularly the SMBIOS and System Parameters settings are not filled in automatically like they seemed they should according to the guide. Attached is a pic of my current / new config vs my 2019 once-stable config. Should I copy some of these values over or leave be? I am able to log in to Messages and Facetime and my iCloud account seems to be working.. although it has asked me to log in again once now because of some vague services error. I can't understand why the Bios ID Version would be different either.

Should I update these values?
View attachment 555367

Congrats on getting the system back! As for your SMBIOS values, I think you should re-use the older ones, because the spec will likely be tied to the iCloud account you've been using until this time. Say you bought some apps before (like Photoshop CC) and you use a different set of serials for this system, you won't be able to use whatever you'd bought before because it is on a new set of SMBIOS serials.

 

[jtnix]

Thanks Middleman. I got another iCloud misconfiguration login prompt after rebooting, so I copied all the SNs from my original config, including the ID in System Parameters. After rebooting again the subsequent login seemed to like it better, time will tell.
Still can't understand why the Bios Version is so different. Is that just another random generated ID on install?

 

[Middleman]

Thanks Middleman. I got another iCloud misconfiguration login prompt after rebooting, so I copied all the SNs from my original config, including the ID in System Parameters. After rebooting again the subsequent login seemed to like it better, time will tell.
Still can't understand why the Bios Version is so different. Is that just another random generated ID on install?

Alright. As for the BIOS version I'm not really sure about that. Maybe the developers updated it from one of Apple's updates on a random basis?

 

[Edhawk]

It is related to the latest Apple Firmware provided for the Mac you are imitating. They get updated by Apple either by standalone Firmware updates or as part of the macOS release.

If you were using a recent version of Clover Configurator it would have the option to 'Update Firmware Only' on the SMBIOS tab. Usually the button is located below the 'Model Lookup' and 'Check Coverage' buttons. Using the 'Update Firmware Only' option would retain the Serial Number, Board Serial Number, SmUUID etc. but update the other less sensitive information in the SMBIOS to match what is expected with a more recent Firmware for an iMac14,2 Mac. This would include changing/incrementing the Bios version.

If you were to ever look to update to Big Sur on this system you would need to be using the iMac15,1 (Haswell Refresh) SMBIOS.

 

[jtnix]

Copying those SNs and IDs fixed the iCloud config, no problems yet on several reboots. So glad to be back in action.

@Edhawk that makes sense about the SMBIOS change, pretty sure my original install was 10.14.4 and I updated to 14.6 along the way.

Thanks for the help everyone!
Jt