Trying to recover an A1311 iMac

Yes, I know and all part of the challenge of recovering thrift store donations - I'm not getting the usual config information from the apple icon on the recovery screen.

Is there another way of identifying which it is?

At what stage do I need to know that?

The model (A1311) is noted underneath the stand, along with serial. What else identifies the models?

It's booting repeatedly to the reboot screen that requires internet, with or without command+option+R

This is https://everymac.com/systems/apple/imac/specs/imac-core-2-duo-3.06-21-inch-aluminum-late-2009-specs.html

So should be able to install Snow Leopard. Good.

Am I correct in believing I need to use Disc Utilities to clear out that locked recovery partition before doing the installation?

Or is there a route to a latest OS internet install that I'm missing?

thanks all!

Thanks, that's what I've got and used previously.

Routine I've used in the past is install DVD, restart and it boots to the DVD, then sort out the HDD and install.

I guess I can then install the latest compatible (High Sierra) from the Play Store?

Thank you all for your help. It's worth real money to the charity that I support.

It's disappointing that the Apple rep who took my call knew none of the above and I'm essentially going to do what I thought I needed to, apart from upgrade from Snow (thanks den.thed)

I've had very good experience with Apple support going above and beyond to help me recover older computers for this purpose when I've hit an obstacle, which is much appreciated. I'll put this less good experience down as a one-off

I declared victory too early

I booted it from the HDD, erased the Mac partition successfully, and tried to use the disc utility to erase the locked partition. It wouldn't unmount.

I booted from the Snow DVD, with quite a lot of drive noise and got through the first couple of clicks on the OS-X installer, selected the only partition offered, the 1TB Mac partition and got a message that it couldn't start up from that partition.

Disc Utility confirmed the DVD and that partition were both good.

I therefore used the utility to do what I've done previously, which is erase the whole HDD. This time, because I'd booted from the DVD it unmounted the locked partition and erased.

Next, I went back to the installer and it still offered and declined to use the Mac partition, so I rebooted from the DVD.

This time it would not reboot further than a folder with a question mark in it after some considerable DVD activity.

Have I taken a wrong turn along the way or unfortunately suffered an optical drive failure at the precise point I needed one?

I do have my own somewhat later iMac and USB drives that I can load the DVD onto and see if I can get this problem child cooperating and then replace the optical drive if that is the only hardware issue.

More guidance requested please!

Old Toad,

I know I have erased the full HDD on the iMac at issue - it's showing as untitled and no other partitions, or at least did when I could last boot it off a DVD.

My challenge is now to get an OS on it with an erased HDD and an apparently misbehaving DVD