Mid 2011 imac 27" with new hard drive keeps shutting down randomly.
After a bad crash, the imac can no longer boot into desktop. I seem to have a stuck booting cycle with the horizontal progress bar progressing then reverting back to the spinning progress circle but never reaching desktop.
I can boot via an external hard drive with a system on and tried to backup the problem drive with superduper. But halfway through backing up the imac randomly shut down. I then restarted using the my external drive and backed up files manuallly.
I also tried installing mavericks on to the problem drive, but the install freezes at the end of the mavericks restart message.
Do you think I have a defective new hard drive? Or do you think it's another issue with the imac?
I may try another option of formatting the problem drive and reinstalling a completely clean system on to the drive.