Black Screen After Mistake Test

I did the petch on the iMac with Open Core a few months ago, even leaving it in Sonoma. The equipment was stopped for about 2 months, until last week when I went to test an Artificial Intelligence APP.

It was fast as ever, an iMac mid 2011 with 16Gb of RAM and 1TB of SSD, flying in Sonoma after an UpGrade of Ventura using unformatted technique.

It was like this: I used the computer for about 1 hour, and I left some Chrome tabs open to resume use after 1 hour, so I turned it off.

1 hour later I turned it on again, but after playing the piano at the entrance the screen froze before I could log in.

I did a good amount of tests with tutorials but I didn't succeed. And in a tutorial it said to select the unit and press enter holding shift.

I did this process with the main drive and nothing happened, but when trying with a secondary drive, the circle with dash appeared, that is, without disk.

After this moment every time when starting, illuminated black screen, same noise from the piano when I turn on... but only black screen in all the tests I did.

Does anyone have any information about these bugs?