Mac won't boot up past log on screen
Mac won't boot up past log on screen. I enter password. It sometimes boots to start screen but within 30 seconds reboots again back to log in or just turns off completely??
iMac 27″, macOS 12.6
Hoping you have a recovery partition.
Hold down the Command-R button at boot, select recovery.
If you get this far the Mac will boot into a 'safe place'.
From there look for DiskUtility and run it.
Link for further reading - Mac startup key combinations - Apple Support