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Question: High Sierra won't install

Ok... Long winded post here. Hopefully I don't miss anything.

I have a late 2009 27 inch imac that I just replaced the dying HDD with a Samsung Evo 840, 250gb SSD. Hardware swap was easy.

I made a bootable usb stick for installing High Sierra. Booted up and selected to boot from USB.

Ran Disk Utility, selected the SSD, which was clearly visible, and erased everything on it, setting it to APFS and GUID.

Worked fine.

Starts to install and gets me to a screen that says simply "macOS could not be installed on your computer. An error occurred installing macOS." No error code or anything like that. Then the option is to "Quit the installer to restart your computer and try again."

Hit Restart and the computer gives the grey screen with the black apple and progress bar. Bar completes one round and goes around for a second shot.

This one gets to about 1/3 done and says "Installing: About 11 minutes remaining" and crashes back to the same error screen, "macOS could not be installed on your computer" and the only option is to Restart.

I've done this, on the off chance that it wasn't a loop, and so far it has been about 6 hours of the same.


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Apr 20, 2018 2:52 PM in response to New MacMan In response to New MacMan

Locate your Software Restore DVDs that came with the computer when it was new. Do the following:

Booting From An OS X Installer Disc

  1. Insert OS X Installer Disc into the optical drive.
  2. Restart the computer.
  3. Immediately after the chime press and hold down the "C" key.
  4. Release the key when the spinning gear below the dark gray Apple logo appears.
  5. Wait for the installer to finish loading.

Snow Leopard Erase and Install

If possible be sure to back up your files.

  1. Insert Snow Leopard DVD into the optical drive and restart the computer.
  2. Immediately upon hearing the chime hold down the C key.
  3. Release the key when the Apple logo appears and wait for the loading to finish.
  4. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Utilities' menu. After Disk Utility loads select the out-dented disk entry from the side list (mfgr.'s ID and drive size.) Click on the Partition tab in the Disk Utility’s right window. Set the number of partitions to one (1) from the drop down menu. Click on the Options button and select GUID, click OK button, set the format type to MacOS Extended, Journaled. Finally, click on the Apply button.
  5. After formatting has finished quit Disk Utility. Continue with the OS X installation and follow the directions.
  6. When the installation has finished the computer will restart into the Setup Assistant. After you complete the Setup Assistant you will be running a fresh installation of Snow Leopard. Open Software Update and install the recommended updates.
  7. Download and install Mac OS X 10.6.8 Update Combo v1.1.

Now, you need to first upgrade to upgrade to El Capitan. El Capitan can be downloaded from the Mac App Store for FREE. To upgrade to El Capitan you must have Snow Leopard 10.6.8 or Lion installed. Download El Capitan from the App Store. Sign in using your Apple ID. El Capitan is free. The file is quite large, over 5 GBs, so allow some time to download. It would be preferable to use Ethernet because it is nearly four times faster than wireless.

See, also, How to download macOS High Sierra.

Apr 20, 2018 2:52 PM

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Apr 20, 2018 2:59 PM in response to New MacMan In response to New MacMan

You may have to attempt to use 'macOS Recovery' online and those Utilities from there

to prepare the iMac for a latest system. Or get Sierra first, since some older Macs don't

like High Sierra installers; could be your Mac is one of those. {..Initial format? old DVD?}

Depending on what the iMac had before the hardware upgrade, these options exist:

• How to download OS X El Capitan - Apple Support

• How to download macOS Sierra - Apple Support

To have/had a clone of previous system (put SSD in external enclosure) to work from is

what some users had found a solution when upgrading to SSD from HDD. Also some

of those SSD installs may do OK, except 'fan sensors' don't register; so fans run high.

OWC DIY Drive Upgrade/Install Kits for Apple iMac Models

The kit from OWC includes a 'sensor solution' when replacing HDD with SSD.

User uploaded file

Apr 20, 2018 2:59 PM

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Apr 20, 2018 2:57 PM in response to K Shaffer In response to K Shaffer

I'm not cloning anything. I want completely fresh. The old drive is crap. :P and the hardware swap went fine, and I will be using a software fix for the fan issues.

Also, when I tried to start up in recovery with network mode, it didn't appear to want to.

Apr 20, 2018 2:57 PM

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Apr 20, 2018 3:22 PM in response to Kappy In response to Kappy

Probably both.

I read your entire reply. It seems to me you're recommending installing something ancient in a roundabout "hack" to get things done. You see, a Google search revealed all of what you said, and I tried it three hours ago already.

Thanks though.

Apr 20, 2018 3:22 PM

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Question: High Sierra won't install