The question of whether you can install Snow Leopard is a matter of the minimum OS supported for the hardware. If your iMac originally shipped with Snow Leopard, then you should be able to install it and your problem is likely a disc or player issue. If you're using SL discs from a different system and your iMac originally shipped with Lion or Mountain Lion, you will not be able to install Snow Leopard on it.
Last week we had something similar; two brand new iMacs, with software and plugins that don't run well on ML.
After some googling we found finally a sort of solution, if you have the original SL disc, you cannot start the mac from it, because the only SL version the iMac will start off, is 10.6.8. The disc version is 10.6.3.
You have to manually start the installation, so the mac will not reboot (because it will not start from the disc)
This is from what I found;
Pop in the Snow Leopard disk, or mount the imange, but instead of double-clicking the installer, click the Go menu and go to System/Installation/Packages (note: there's no leading slash. You're not navigating to the System on the root drive, you're navigating to the System on the installer). Find OSInstall.mpkg and double-click. "mpkg" is a meta-package, or a package full of other packages. This is the installer that launches when you boot off the disk.
Install on a clean partition, and use the Combo updater, then it should start from 10.6.8
After some fiddling we now have two iMacs running Snow Leopard (which is still the best)
It seems that the problem can be tracked down to ML itself rendering the superdrive useless - well that's the what users are saying:
I hadn't used it since upgrading and now it doesn't work.
There are a number of suggested solutions - none worked for me, i.e. resetting PRAM SMC etc., etc..
I might have to hold out until the next upgrade - which may or may not solve the problem.
I wondered if it was possible to extrat the install files from the DVD on a PC but it only allows you to see the relevant PC files for a Bootcamp setup.
I suppose an external DVD drive might work - but what a waste of money.
W.M. Bravenboer wrote:
Isn't it possible to buy SL in the Apple Store and download it?
Or else to get the installer files on a USB stick?
I understand you can't see any DVD or CD in your drive under Mountain Lion?
Unfortunately, Snow Leopard is only available in DVD format. It would be possible for the original poster to create a USB version of the discs, yes, but that entails a working drive first.
I did try your suggestion, but the drive still wouldn't work....However....
I have actually managed to get a disc image of Snow Leopard, but of course ML won't let me open it so I've gone back to your original post, but am not sure where to find the system folder you mention.
If we're talking about the same thing!
Can you mount the image? Or else unpack it?
Make sure you have the OS X Install DVD window active, in the finder click 'Go' and 'Go to Folder' (Shift-Apple Key G) and enter 'System/Installation/Packages'
Then a window should come up with a lot of '.pkg' files, find the file that says 'osinstall.mpkg'
double click this, and should start the installer, without the need to reboot...
If you have installed SL, do not restart, but install the combo 10.6.8 update, this should work, and then you can restart the mac into SL...
Hope this works!
That's great it really did install SL to the new partition, the problem was I couldn't boot into it. The newly created partition wasn't appearing in Start Up Disc or wasn't bootable from start up holding down alt. I also was receiving a progress bar on start up which apparently indicates problems. I could however see all the newly created files in the new partition from within Mountain Lion.
So I recreated the partition from scratch and didn't install SL and the new partition still wasn't appearing, which means the trying to install SL probably wasn't the problem.