Mac wont start after Big Sur
My iMac wont start after upgrade to Big Sur
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My iMac wont start after upgrade to Big Sur
Even if you’ve already done these basic resets do them again, two or three times each.
Reset the SMC How to reset the SMC of your Mac - Apple Support
Reset the NVRAM Reset NVRAM or PRAM on your Mac - Apple Support
After you boot into safe mode and shut down will ot boot again in safe mode?
Even if you’ve already done these basic resets do them again, two or three times each.
Reset the SMC How to reset the SMC of your Mac - Apple Support
Reset the NVRAM Reset NVRAM or PRAM on your Mac - Apple Support
After you boot into safe mode and shut down will ot boot again in safe mode?
Thank you for your input. I tried this and several other online suggestions. Right now I have reinstalled Mohave. I tried a fresh update to Big Sur and everything went well until the very end where it says it has to shut down to complete the installation. It shuts down, won't complete install and becomes a brick. The only way I can get back in is Power/Command-R to disk utility. Now I running Mohave but can't turn off the computer at all. It won't restart. It wakes up fine from sleep mode.
Same issue after Big Sur upgrade only my computer won’t turn on at all. Nothing happens when I press and hold the power button. Can’t enter safe mode or any of the other start up options. What has happened and how do I fix it?
Just a quick follow up and "Thank you". I went through the resets multiple times, but computer still wouldn't boot up (even in safe mode). Reinstalled Mohave and stayed with that until I could see a significant window of time. These failed upgrade attempts were leaving me stranded for hours. Tried the resets again. I also opted to install any Mohave patches or updates I could find. Not sure which one did the trick but when I hit the upgrade to Big Sur button, it worked! The process went smoothly, and the computer rebooted just like it should. Thank you again for following up and your suggestion.
Try booting into safe mode How to use safe mode on your Mac - Apple Support the restart normally.
Mac wont start after Big Sur