Étienne BERSAC, as per https://support.apple.com/en-us/HT201518 an update to your computer's buggy and outdated BIOS is available (IM121.0047.B21). If you update to this following https://help.ubuntu.com/community/BIOSUpdate does it change anything?
If it doesn't, could you please both specify what happened, and provide the output of the following terminal command: sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date For more on BIOS updates and linux, please see https://help.ubuntu.com/community/ReportingBugs#Bug_reporting_etiquette . Please note your current BIOS is already in the Bug Description, so posting this on the old BIOS would not be helpful. Also, you don't have to create a new bug report. Once the BIOS is updated, and the information above is provided, then please mark this report Status Confirmed. Thank you for your understanding. ** Tags removed: latest-bios ** Tags added: bios-outdated-b21 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1452858 Title: Screen lit off on iMac 12,2 after a while To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1452858/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
