No boot options or recovery screen after gpu upgrade

[SickVoodoo]

Maybe I did to much at once or did things in the wrong order but I’m stuck.

My main goal was to install Catalina on my mid 2011 21.5 iMac.I researched steps and compatible GPU’s and ordered the parts. Install went fine.

Installed a i7 2600s cpu and a Nvidia Quadro K2000M
Computer boots and runs great missing the dimming and boot screen like expected.

The problem I’m having is when running the Catalina patch tool I need to boot from the install disk and I get nothing but black. Shutdown computer, power on and hold down the option key, and nothing but black.

I looked into updating the gpu information to gain the boot screen manually but that just confused me more. Any info or guidance is appreciated. Thanks

 

[MacGizmo]

What "install disk" are you trying to boot from? A USB drive? If so, Catalina requires you to make a security adjustment to allow booting from external USB drives.

 

[SickVoodoo]

My question doesn’t fit this location like I thought it did at first. I’m currently running High Sierra trying to update to Catalina with a patch for install on older Macs. I found a thread that’s helping and when I figure it out I will post my fix here to make it easy for someone else to find.