MP 1,1-5,1 Trying unsuccessfully to upgrade with OCLP on 2012 cMP

[Major G]

I have a 2012 cMP 5,1 currently running Mojave 10.14.6 and I want to install Monterey with OCLP.

I followed the steps and have it installed on a thumb drive, but when I reboot and hold down the option button, it doesn't work. I don't get the option to load the EFI from the thumb drive. My mac won't start correctly when I use the restart function. I always have to shutdown and then power back up.

Do I have a firmware problem? Why won't the "Hold option key down while restarting" not work like it is supposed to? Any assistance will be very much appreciated!!

 

[Macschrauber]

You give no detailed information about your hardware setup.

I wild guess you have no GPU what displays pre boot information. Aka bootscreen.

 

[Major G]

I have a Radeon RX580 8GB installed. I get the white screen with the apple symbol, and then the sign in window when I boot up. I don't hear the chime when it boots, but my monitors only power up after getting some signal. (Focal monitors) 96GB of RAM. Four hard drives of at least 1TB each. What other info might be helpful?

 

[retrovox]

When prompted to build and install Opencore, suggest you install it directly into the hard drive instead of a USB thumb drive. Try and see if it works.