iDimaxum Author

Level 1

4 points

iMac boots only on external HD?

Hi,

My iMac boots only on external HD.

Sinds saterday when I installed on my external backup High Sierra I can't see my internal HD anymore. When When I go System Preferences - Boot devices I only see the external drive showing up. No HD and internal Backup HD are showing.

I did already NVRAM, did nothing change ...

I did already Reboot+R, did nothing change ...

I looked around on the internet, but no similar problem I could' find to solve this.

What is the cure to solve this issue I have ?

Hope that one of the Mac goeroes can help my out.

By the way ... my forum name is Dimaxum level 5 I believe, but I hat to make a new account because I couldn't login. My pasword was rejected?

Thanks, Dimaxum

iMac midd 2011

Earlier Mac models

Posted on Sep 25, 2023 3:25 AM

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14 replies

Level 10

90,922 points

Sep 25, 2023 4:00 AM in response to iDimaxum

That sounds like your internal hard drive is no longer formatted correctly as a startup disk.

see > Use Disk Utility to erase an Intel-based Mac - Apple Support

and the Intel Install instructions at > How to reinstall macOS - Apple Support

Please note: that Erasing and Reinstalling the macOS will wipe everything on that drive.

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Level 10

90,922 points

Sep 25, 2023 3:32 AM in response to iDimaxum

From your description, it sounds like the internal hard drive has failed.

Can you see and repair the internal drive with Disk Utility?

Repair a disk using Disk Utility on Mac - Apple Support

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Level 10

90,922 points

Sep 25, 2023 5:27 AM in response to iDimaxum

Yes you should be able to erase and format the internal drive while running from the external drive.

If you can't, then you need to do in while in macOS Recovery Mode.

High Sierra requires APFS as shown in the Erase article that I posted above.

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iDimaxum Author

Level 1

4 points

Sep 25, 2023 3:45 AM in response to den.thed

Hi den.thed,

Thank you for passing by.

Yes I can see the HD in Disk Utility, and I repair it twice ...

I can see all of the Disks HD and internal backup HD, but not in System preferences.

Also, when running repair dist ... the disk is okay.

Dimaxum

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Level 10

90,922 points

Sep 25, 2023 4:15 AM in response to iDimaxum

No. You will need to reformat and reinstall as per the instructions, to make that drive bootable again.

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Level 10

90,922 points

Sep 25, 2023 7:17 AM in response to Dimaxum-1

You should see a Solved or This Answered my Question button.

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iDimaxum Author

Level 1

4 points

Sep 25, 2023 4:09 AM in response to den.thed

Hi den.thed,

Is there now other way to get back my HD?

The problem is that I could'n install High Sierra on my iMac HD, because the guy who prepared and sold me the iMac didn't setup the internal HD drive in portions. He used the whole HD to install everything that is on it. So, thats why I used my external HD for installing High Sierra. I had many issues that I did not see in Safari websites when I visit them.

Dimaxum

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Sep 25, 2023 6:02 AM in response to den.thed

Hi,

Guess what ... I managing to reinstall the system from the internal HD back. Everything works fine ... So, back to macOS Sierra until I made up my mind.

Thank you for you time and effort ...

Kind regards,

Dimaxum

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iDimaxum Author

Level 1

4 points

Sep 25, 2023 4:31 AM in response to den.thed

Okay,

Can I after words formatting the HD reinstalling from the external HD that is now running High Sierra ...

What kind off portion on the HD you recommending?

Dimaxum

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iDimaxum Author

Level 1

4 points

Sep 25, 2023 4:52 AM in response to den.thed

Hi again,

HD "Partition" not portion.

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Level 10

90,922 points

Sep 25, 2023 6:41 AM in response to Dimaxum-1

Good work, you're welcome.

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Sep 25, 2023 6:54 AM in response to den.thed

Dear den.thed'

Thank you ... how to make this treat as "SOLVED"

Dimaxum

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Sep 25, 2023 7:45 AM in response to den.thed

Tak you, I did ...

Solved.

Dimaxum

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Level 10

90,922 points

Sep 25, 2023 7:56 AM in response to Dimaxum-1

You're welcome.

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iMac boots only on external HD?

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