Any re boot advice?
My 2012 iMac, High Sierra 10.13.4, will not complete the boot sequence. It gets to the Apple logo, the bar under the logo runs to about three quarters of it's length, it cuts to the white screen. It stops on the white screen and freezes.
I am not sure if 'Safe Mode' is working. I tried rebooting by holding down the power button and pressing the shift key but it goes through the same sequence.
It did change to a grey screen which allowed a choice of the setup screen which allowed me to select the hard drive and I did get it to boot up to the desktop but it quickly returned to the white screen again when I tried clicking on Safari.
Does anyone know a way to do a check on the boot sequence or access the safe mode in another way? If I do get back to the desktop is there a check sequence which will find why it reverts to the white screen? Any helpful suggestions will be gratefully welcomed.
iMac, macOS High Sierra (10.13.4)