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New USB SSD on iMac not working

I have chosen a new USB SSD as the startdisk of my iMac. When I boot my iMac I get this error on a black screen "Your computer restarted because of a problem. Press s key or wait a few seconds to continue starting up"


Before all this I erased my new SSD in Disk Utility and I chose the GUID partition and Mac OS X Journaled (extended). Then I restarted and pressed cmd+R. I copied the HDD with all data to the SSD and afterwards changed the startdisk to the SSD and named it SSD. Then I get the error I wrote before. What did I do wrong?


Specs:

The iMac (late 2015)

SSD Samsung T7 500 GB

Posted on May 19, 2021 12:42 AM

Reply
Question marked as Top-ranking reply

Posted on May 19, 2021 3:45 AM

OK, let’s start over. Please follow the instructions here: How to Setup and Use an External SSD as y… - Apple Community.


Cheers,


Jack

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4 replies

May 19, 2021 3:30 AM in response to Jack-19

I do not get where your reply is in this thread, but Jack-19 replied:

Well, first I don’t ever use Samsung SSDs, but hopefully that is not the issue. 

Do you need to stay on macOS High Sierra, or can you upgrade to macOS Big Sur? Have you erased your internal drive yet?


My answer:

I hope not that is the issue :-/

I am on Big Sur. The internal drive is not erased. I dare not to erase the drive yet.

New USB SSD on iMac not working

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