It's unclear what you mean with "boot". Usually you don't boot from an external drive.
I'd start with trying another disk in that same case, to see if that is fine (preferably formatted FAT32 or Mac file system). An I would try this disk in any case on a Windows or Linux PC. If it's a Mac file system you won't be able to read it, but it should be recognised in any partition program.
Did you realise that ultra important files must be backed up ultra well? And that external disks aren't reliable enough to store your only copy of any file that you don't want to lose, even the moderately important ones?
Hi all,
I have an ultra important file on my external HDD (Seagate 2TB, 2.5" on USB), but disk isn't showing up anymore (iMac)
This is the situation: it worked okay, until I got an error message that it was unsafely removed. The USB connector on the case was loose for a while already, that was the problem. So I put it in another case (just plugged the SATA from the HD in the new one).
That works fine, I hear the disk turning and the blue LED on the case is on, so it gets powered by my computer. But the disk doesn't show up on my computer...
I checked disk utility and it's not even there, the USB is not even recognized in the hardware info when you click on Apple logo.
I hope my files are not deleted?
How can I boot this disk again?...
Thank you so much,
Michael

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