Contribution d'origine par : Dan ,
While Apple did have an issue with some MacBook Pro’s with the upgrade failing. I have not heard of any issues with the iMac’s [https://www.forbes.com/sites/barrycollins/2020/11/20/macbook-bricked-by-big-sur-heres-how-to-fix-it/?sh=178237d1663e|MacBook Bricked By Big Sur? Here’s How To Fix It]. The issue is with the I/O board in these systems. So… I would visit an Apple Store to see what they say with both systems in hand. They should be able to address the issue if it was a Big Sure defect.