I'll try to keep this as short and sweet as possible. 1) This has happened many times (every 3-6 months) over the last 3 years I've had the iMac but I always manage to fix it after multiple attempts with Disk Warrior. Easier than a trip to the Apple Store. 2) iMac will shutdown randomly and then when I power it back on it will show the loading bar on the gray apple logo screen and then shut off before reaching 100%. 3) I boot into target disk mode and a lot of the time it won't mount the main drive (256 SSD), only the secondary drive (2TB HDD) in the imac. 4) After finally managing to get the system drive to mount I am usually able to repair it with Disk Warrior and then its good for another 3-6 months. In some of the attempts Disk Warrior will fail and say that it cannot repair the drive due to a hardware failure. 5) Currently running Mavericks, but this happened in ML and Lion as well. So this has happened again and after many attempts of trying to get the computer to mount in target disk mode and I finally got it mounted and am currently running carbon copy cloner to backup all of my files. Does anyone have any idea what might be causing this? It says hardware failure at times but Disk Warrior in the past has patched things up and it runs fine for another few months. I have an apple store appointment on Saturday and do not want to repair it so they can see it broken. I don't want them to just repair the drive with some app and send me packing as my AppleCare runs out in a few months. Any help or thoughts are much appreciated. Thanks!