iMac problem Mid-2010

Discussion in 'iMac' started by Tech198, Aug 6, 2019.

  1. Tech198, Aug 6, 2019
    Last edited: Aug 6, 2019

    Tech198 macrumors G5

    Mar 21, 2011
    Australia, Perth
    My friends got an iMac-2010 at his workplace, currently uses El Capian, he wish to download back to Snow Leopard 10.6.3 (specially, as i've heard once you apple firmware update, it cannot be lower), I think his iMac is 21".

    The problem is he bought retail Snow Leopard disc (Retail) from Apple store, as he lost his grey discs.

    He cant boot from disc, because "c" doesn't work....... I thought it may be keyboard issue, as he can't even get to startup manager either(Alt/Option)

    Within El cap, i asked him go to to system preferences/Startup Manager, and select DVD, click "Restart" and he said all he saw was Apple log, (a long time he waited) and didn't go any further.. Now he has issues getting disc out... Although sometimes he can, the fact is its not booting.

    I think the root of the problem though is can't he downgrade his 2010-iMac from El Captan to retail version of Snow leopard. He said the disc is defiantly 10.6.3 and white color, a Retails disc,..

    As he tried a 'grey disc' from another Mac, which obviously different work due to hardware differences. Since the OEM is designed for the Mac you bought it with. He doesn't use Time Machine either, so he couldn't restore from that.

    Main reason he wants to downgrade is because Adobe CS6 only works up to Yosemite. I dunno why he wants to go back to SL, but if it can't read disc, then that's the first problem. Possible hardware issues?

    From Apple's tech specs: His iMac 21.5' shipped wit 10.6.3 so even after upgrading to elcap, he should be able to go back with he disc shouldn't he?
  2. wardie macrumors 6502

    Aug 18, 2008
    You sure that is correct? I would have thought it’s just the standard release of whichever OS it is and the install process customises it for the right mac. Maybe with the exception of bespoke releases for specific niche pro models etc.
  3. nambuccaheadsau macrumors 68000


    Oct 19, 2007
    Nambucca Heads Australia
    Try using Option when he boots up with the CD in the iMac.
  4. mikehalloran, Aug 6, 2019
    Last edited: Aug 6, 2019

    mikehalloran macrumors 68000

    Oct 14, 2018
    The Sillie Con Valley
    You've heard wrong.

    Yep. The retail DVD is earlier than the pre-installed OS (10.6.3) or the restore disk which needs to be 10.6.4.

    Even after all the firmware updates, it can be made to boot and run 10.6.4 from the AppleCare Restoration DVD. I tested mine a few months ago—no problem.

    I had my mid-2010 running Mojave. It sucked because if the GPU incompatibility but it did work.

    I had to limit mine to OS 10.13.3 because of an eGPU issue. Apple crippled it on 10.13.4–6 but, once I reverted, no problems at all. Now that I no longer need to run 2 side monitors, it runs 10.13.6 beautifully.

    It's very easy to replace the hard drive with an SSD. There's a cheap-o way to bypass the Temp sensor (Do Not Do this with a mechanical hard drive — HDD).
  5. mikehalloran macrumors 68000

    Oct 14, 2018
    The Sillie Con Valley
  6. mikehalloran macrumors 68000

    Oct 14, 2018
    The Sillie Con Valley
    You can make an install USB stick of any OS from 10.6.8 to 10.13.6. It needs to be 8G or larger and some of the new, cheap ones don't work.

    There are instructions everywhere. You will need to get the installer from someone or download it. If you get the installer from another Mac, zip (archive) it first before you move it to the Mac that you use to create the installer and un-zip it there.

    How to Make A Bootable USB Disk of OSX

    Have a backup. A Time Machine or your old Mac is fine as long as the backup is not a newer OS than the one you are trying to install.

    Download the correct complete installer. When it tries to run (or tells you it's too old to run on your Mac), Quit. The installer will now be found in your Applications folder. Leave it there.

    Insert your 8GB or larger USB external stick/drive*. Change the name to MyVolume. This is important or the following Terminal Commands will not work. This process will erase, reformat and rename the drive to that of the OS installer.

    Launch Terminal from /Applications/Utilities and enter the command below (copy & paste) and then your password when prompted.

    High Sierra

    sudo /Applications/Install\ macOS\ High\ --volume /Volumes/MyVolume --applicationpath /Applications/Install\ macOS\ High\


    sudo /Applications/Install\ macOS\ --volume /Volumes/MyVolume --applicationpath /Applications/Install\ macOS\


    sudo /Applications/Install\ macOS\ --volume /Volumes/MyVolume --applicationpath /Applications/Install\ macOS\

    El Capitán

    sudo /Applications/Install\ OS\ X\ El\ --volume /Volumes/MyVolume --applicationpath /Applications/Install\ OS\ X\ El\


    sudo /Applications/Install\ OS\ X\ --volume /Volumes/Patriot --applicationpath /Applications/Install\ OS\ X\


    sudo /Applications/Install\ OS\ X\ --volume /Volumes/MyVolume --applicationpath /Applications/Install\ OS\ X\

    Terminal will tell you when done. Insert the USB Installer into the Mac you wish to install. Shut down. Hold the Option key on startup. Select the installer drive. After it boots, you may have to run Disk Utility from the Installer to update the drivers or reformat/erase the drive if downgrading the OS before the installer works. Quit Disk Utility and run the Installer.

    High Sierra/Mavericks may run firmware updates and will format an SSD to APFS by default. If you don't want this, you can change after the OS install in Disk Utility— it will erase the drive.

    *Some recent inexpensive USB sticks will show a correct installation and are visible in an Option boot but will not work—you'll get the circle with the line across. If you encounter this, use another brand of USB stick. Older and expensive ones always work. The $5.99 cheapo from Best Buy doesn't.
  7. Fishrrman macrumors P6


    Feb 20, 2009
    OP wrote:
    "Main reason he wants to downgrade is because Adobe CS6 only works up to Yosemite"

    Are you sure about this?
    I have Lightroom 5.7.1 running just fine under Mojave 10.14.6.
  8. mikehalloran macrumors 68000

    Oct 14, 2018
    The Sillie Con Valley
    Yes, CS6 has been 64 bit for a long time now. It was 32 bit when released in 2008 but Adobe has been updating the components over the years.

    I have some older 32 bit Adobe products still running over Mojave. Although I have later versions of Photoshop Elements 6 and Acrobat Pro X, I use these versions in my day gig as they have exactly the features I need.

    I have later versions for when Catalina comes around and will use them but, till then, what works (quite well), works.
  9. retta283 macrumors 6502a


    Jun 8, 2018
    Kingman, AZ
    If you have another Mac that can run SL and has FireWire, you can use Target Disk mode. Just connect the two, boot the iMac into target disk mode, put the Snow Leopard CD in the other Mac, and select the iMac's drive to install to. Once done, you'll need to update to 10.6.8 before using it with the iMac. Once that's done it should work fine.

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8 August 6, 2019