We can try some basic troubleshooting steps and see if that works or not. First we can reset the PRAM and NVRAM of your Mac. Reset PRAM and NVRAM
If that didn’t work, then restart your Mac in Safe Mode. To do so, make sure that the computer is shut down. Press the power button. Immediately after you hear the startup tone, press and hold the Shift key. Release the Shift key when you see the gray Apple and progress indicator. Let the Mac boot up to safe mode.
If Safe Mode doesn’t work, run Disk Utility in Single User Mode. Follow the steps below;
Turn your Mac off. Turn it back on and this time hold down the Command (Apple) key and the S keys at the same time. Then type the following command... /sbin/fsck -fy (note the space between fsck and -fy) If you can't run /sbin/fsck - fy then type only fsk - fy Hit return and the disk utility should run and let it finish. When it finishes and there is no error, then type reboot and hit return. Let the Mac boot up. (Disk Utility will fix all system errors, bad preferences files etc)
Please let me know if that doesn't work, so we can continue troubleshooting.
None of these worked. disk utility seemed to run but there was no way to type reboot
Tried this twice and get a bar across bottom which loads a little but then just grinds away.