How to get iMac 11.1 back to original High Sierra after using OpenCore-Patcher V1.30

[Albert4510]

I have an iMac late 2009 and it was equipped with HighSierra 10.12.6

A few days ago I installed Sonoma here using MacOS Installer.

This is to determine whether the latest version of FinalCutPro (FCPX) would function on it Unfortunately, this did not work because the video card was no longer suitable for this (not Metal suitable).

But the rest it worked fine. However, I now want to go back to the original High Sierra 10.12.6.

But I'm not a computer guy and I don't know how to do this exactly (step by step).

Of course I searched for a long time on the internet and on YouTube, but unfortunately I didn't understand it or couldn't find the right explanation.
Maybe it is no longer possible?

an someone help me?
That would be very nice.

 

[TheShortTimer]

Edit: inaccurate advice removed!

 

[Amethyst1]

A 2009 iMac can't do Internet Recovery, so if the "normal" Recovery partition doesn't do it, the OP will need to download a High Sierra installer and use createinstallmedia to create a High Sierra USB installer.

 

[TheShortTimer]

A 2009 iMac can't do Internet Recovery, so if the "normal" Recovery partition doesn't do it, the OP will need to download a High Sierra installer and use createinstallmedia to create a High Sierra USB installer.

I forgot about that: silly me!

Thank goodness you're here.

 

[Albert4510]

Dear TheShortTimer,

Thanks for the instructions.
This got me back on track and now this Mac is back to how it was originally (i.e. with original High Sierra).

My thanks again.

 

[TheShortTimer]

Dear TheShortTimer,

Thanks for the instructions.
This got me back on track and now this Mac is back to how it was originally (i.e. with original High Sierra).

My thanks again.

Are you sure that it's not @Amethyst1 who got you back on track?

Delighted that you're up and running with High Sierra again, though.

 

[Albert4510]

Sorry,
Copied the wrong persons name :-(

Ofcourse, the credits go to Amethyst1

 

[Amethyst1]

Credits, shreddits: the iMac‘s back in game, that’s what this thread is about.