Bricked macmini3,1: prohibited sign

[Duffy6]

Hi!

I bought a macmini3,1 and updated it successfully with dospatcher1 to Catalina.
After that I used oclp and wanted to update to Big Sur.

This went wrong: I see question mark or prohibited sign.

If I do NOT press the option key at boot I get a big question mark when booting.


When I DO press option key I only see one HDD-partition (and not even the USB-Stick).
When I then choose the only available prtition (named bigsur) I see a prohibited sign.

Any idea how I get this machine running again?
Best would be with Big SUR!

Thx

Regards
Duffy6

 

[DeltaMac]

If you Option-boot to get the boot-picker screen, you should see an EFI partition as one of the choices.
If you do not see an EFI partition, did you install OpenCore on whatever you are using for a Big Sur installer disk? That needs Open Core, so when you hold the option key on boot, you can choose the EFI partition first, then press return. You will then see the real Big Sur installer, as the icon will change. It's all about the right sequence with OCLP: Insert your Big Sur installer. Boot/Reboot, holding Option. Choose the EFI partition. Press Return. Now, choose the OCLP Big Sur, and press enter again. Should work this time. Just a tip: I have 5 different Macs, each running different macOS versions, and each with at least one boot system, with each running some version that needs OCLP. I have finally learned that I have to monitor the installs, always watching for reboots (updates usually do 4 to 6 reboots, and I always hold Option on reboots, just to make sure that the EFI is accepted, and then the next install step is (usually) pre-selected, and I just press enter to move ahead with the install.
Usually works OK.

 

[Duffy6]

Thank you for your reply.
As I do not see any UFI boot option and also no USB-Stick Boot Option:

Hoe can I unbrick this macmini3,1?

 

[Bigwaff]

I bought a macmini3,1 and updated it successfully with dospatcher1 to Catalina.
After that I used oclp and wanted to update to Big Sur.

Did you attempt to install OCLP Big Sur over top of DosDude Catalina partition? Or did you partition disk for separate installations of macOS?

 

[Duffy6]

While installing OCLP I used the installer-built-in disk tool to format my complete HDD in AFPS and GUID.
Then I installed install and it was bricked.
Did I do anything wrong?
What's the right behavior to install?

 

[Bigwaff]

Insert USB stick. Hold option key down while restarting. If you don’t see USB stick, try different USB port. If after try all ports and you still don’t see USB stick, you need to start over from scratch. Recommend you attempt to reinstall compatible version of macOS first using Internet Recovery. Recommend use wired Ethernet, no Wi-Fi. Also consider whether to upgrade HDD to SSD first. OCLP supported macOS versions all APFS, which is optimized for use with SSD.

 

[Duffy6]

I could solve the prohibited sign by installing Snow Leopard (10.6) with the CD.
Now I wanted to directly use OCLP to upgrade to BigSur. But OCLP requires 10.10.

How do I manage that? First use dospatcher1 and then OCLP?

 

[DeltaMac]

You have to install OpenCore on your USB installer for BigSur. If you don't see the EFI partition on the boot picker screen, there's no way to boot to the installer (or it won't correctly boot, and you will get the prohibited symbol - or, the blinking disk. Either one basically means that you don't have a correctly made bootable installer, and most likely one that you have not yet added the OpenCore to the disk.
Don't try to upgrade a Mac that has a patched system, such as that from dosdude1. If you need 10.10 (Yosemite) or higher, then you will have the best chance at the result that you want. Use that to make your Big Sur installer. I think you are asking for problems if you try an OCLP installer on top of a dosdude patched system (I think the patches can be incorrectly installed if you try to mix the different patcher systems.) I remember seeing somewhere that if you encounter a Mac with a dosdude patched system, and want to go with OCLP, that you should erase that older patched system, and make the OCLP install to a freshly erased drive, that is, a completely clean macOS install.

Maybe you have a newer Mac, perhaps that has a newer macOS system, my favorite system is one that has Big Sur already. Use that Mac to make your installer USB, then install OpenCore on the installer USB, choosing to make the OpenCore for the Mac that you want to install Big Sur. It's just choosing the Mac model (MacMini3,1) from the menu. And, that selection will allow you to install OpenCore for your macmini3,1. That's how you can boot the macOS installer from your MacMini. If you don't get that set up properly (including choosing the correct Macmini3,1 for the OpenCore installer drive,) you will just be wasting your time. When you have the correct setup for OpenCore on your installer drive, then your MacMini drive can be erased--you don't even need a system installed, just install the new system on an empty drive.
By the way, DON'T erase the internal drive, and format with APFS. GUID is fine. If you want to install 10.10 first, THAT installer won't accept the APFS-formatted drive (10.10 doesn't know what APFS is). Just format as MacOS Extended. And THAT drive, when you then install Big Sur, will be automatically changed to APFS. The Big Sur installer takes care of that. There's no reason to set that up as APFS before upgrading to Big Sur.

 

[Duffy6]

Thank you guys for your patience with me.

What I did today with my macmini3,1:
1) Rolled back to a clean Snow Leopard install (with original CD)
2) installed dosdude1 patcher (to Catalina) - I did that just to execute the OCLP patcher to create a USB-installer for Big Sur
3) installed Catalina with dosdude1 patcher USB-stick
4) executed the OCLP patcher and created a USB-installer for Big Sur
5) Rolled back to a clean Snow Leopard install (with original CD)
6) tried to install Big Sur with the OCLP installer USB

buuuut: I could see a EFI boot option with the OCLP installer :-((

This took me hours and hours!

Can you please give an advice what I did wrong?

 

[DeltaMac]

Can you tell us what happened in step 6, when you tried to install Big Sur?
Did you actually choose the EFI option, followed by choosing the installer when it appears AFTER choosing the EFI option (don't forget to choose the EFI option first, then followed by choosing the installer. That's how this all works with OCLP! )
my explanation here:
The boot choice, when working with OCLP, is always a two-step process. If you see the EFI boot option, select EFI, then press Return, then select your Big Sur installer, and finally press Return. When you get a reboot during the install (there will always be several reboots), always hold the option key, and choose EFI first, then watch to make sure that the boot will continue with what the installer has pre-selected. It should be showing as a boot choice that is already selected-- and you can simply press enter when you see that, although the installer will time out after a few seconds, and continue to boot on its own. I like the watch at the reboot, just to make sure about the EFI boot, then the boot that always follows.
One more thing... There's absolutely no need to "roll back to a clean Snow Leopard install." Installing Big Sur will put everything in place that you need for a system install, (except for your own apps and files, of course.) You would continue to choose the EFI partition on your installer drive on any reboot during the final setup process, when you can boot to the new system, and then install the Root patches and the Open Core install on the internal boot drive.