Chosen Solution
Hi, I have a 2011 iMac running on High Sierra that cannot get past the boot screen. I had success booting in recovery mode and checked the drive using Disk Utility - all good. I’ve performed a clean reinstall of High Sierra - same problem. I’ve performed a clean install of Mojave (using a patch, I know, my bad) and that worked great up to a point - the graphics card struggled under the Mojave OS. So I am trying to clean install High Sierra again but I cannot get past the boot screen (stays on grey screen after Apple logo). I’ve attempted all the Mac boot modes (cannot get in recovery mode now), swapped the drive out, purchased and installed the OWC Thermal Sensor but still cannot get past this boot up screen. Am I toast? Thanks, Simon Manchester UK
Do you have another Mac system which you can create a OS Installer drive (USB thumb drive)? I would jump back to Sierra using this installer How to upgrade to macOS Sierra jump down to Step 4. Click on the Blue URL link “Download macOS Sierra” And follow this guide to create the installer How to create a bootable macOS Sierra installer drive See if reformatting the drive fully gets you going using this drive to boot up your system.
