iMac Pro went in to Recovery mode after power loss during update, now won't even restore after DFU mode

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iMac Pro went in to Recovery mode after power loss during update, now won't even restore after DFU mode

Whilst updating my iMac Pro T2 the power went off for an instant, the iMac went in to recovery mode and tried to restore from network, but couldn't. No doubt as "Boot from External Source" is disabled by default. So, needless to say, it wasn't going to be an easy USB drive Job. Never fear my little MacBook Air M3 and cables are here however this did go in to DFU mode and erased the disk (or so its said) on my iMac. However be it Ethernet nor Wireless connection cannot revive the iMac, it just errors out after about a few mins to an hour, yes PRAM has been done. I have my original proof of ownership and serial number, does that reset email that Apple provides can reset remotely? or is there something I am missing. Any suggestions gratefully received.

Thx Bob

iMac Pro, macOS 14.7

Posted on Feb 8, 2025 04:57 PM

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Answer 1

Owl-53

Level 10

100,285 points

Feb 9, 2025 02:22 AM in response to Bobbins321

OUCH

You mentioned " Reviving " and no success

May need the Restore as a last resort before venturing to the Apple Genius Bar

How to revive or restore Mac firmware

excerpt from above

" Restore "

Try reviving your Mac first. If your Mac can't be revived, follow these steps to erase it and restore it to factory settings.

From the DFU window in the Finder, click Restore Mac. Then click Restore and Update to confirm.
A progress bar in this window shows that the restore is underway. When the restore is complete, the affected Mac restarts automatically. If it shuts down instead, press the power button to turn it on.
If asked, select a Wi-Fi network or attach a network cable.
Mac with Apple silicon:
1. If asked, sign in to the Apple Account previously used with this Mac.
2. When the setup assistant opens, use it to finish setting up your Mac.
Mac with T2 chip:
1. The restored Mac shows a spinning globe as it starts up from macOS Recovery over the internet. Choose your language when asked.
2. If asked, sign in to the Apple Account previously used with this Mac. Then click Exit to Recovery.
3. When you see the list of utilities in Recovery, choose the option to install or reinstall macOS.
4. After macOS installation, the Mac restarts and opens the setup assistant. Use it to finish setting up your Mac.

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Answer 2

Bobbins321 Author

Level 1

5 points

Mar 20, 2025 05:56 PM in response to Owl-53

Many thanks for your reply, it turns out I stated in recovery mode and allowed it to update to OS Sequoia, which it did successfully and then in recovery I removed the option "to not allow booting from external media" and everything is good.

That was the problem and my inability to access it, was the major problem, needless to say set on "Medium Security" & "Allow booting from external Media"

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Answer 3

Owl-53

Level 10

100,285 points

Mar 21, 2025 04:45 AM in response to Bobbins321

Thank you for the updated info

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