Hello everyone. I own a mid-2011 iMac, with a 100GB HFS+ partition (which contains Yosemite OS and some files), a 700GB NTFS partition (containing movies, music, documents and so on) and some free (non allocated) space in which there was Windows OS; but I deleted it some time ago. There is of course the EFI partition too. I have 8GB of RAM. Three days ago, it stopped working. I was using Spotify, Google Chrome and InDesign, so the computer was heavily loaded, but that never was a problem. It rebooted; the problem is the fact that it can't boot anymore. When I manually start the computer via the proper button,it reboots when the progress bar is barely at its half, and it keeps doing so over and over. I'll list you what I've tried and what I've learnt: I tried to use the Recovery Partition. It fully loads, but, when the progress bar is full, a white screen appears and it does nothing at all; I've tried to keep it running but after 5 hours I decided to shut the computer down. I tried to download the Recovery Assistant (via CMD+R); I can download it, but when the download finishes the white screen is shown and there's no way to do anything. I used a live Linux distribution to access the HFS+ partition. I ran GParted, I did all the possibile checks on every partition and no problems were found. I also found that the files in the HFS+ and the NTFS partition are still there: so, there aren't (it seems) physical problems on the hard disk itself. I used CMD+V and check the verbose debugging: no signs of things going wrong. I also used CMD+S to ran the OS in single mode. I ran fsck -fy and there weren't problems on the HFS+ problems. I couldn't use diskutil commands because it's not allowed in single user mode. I booted an USB device contaning a bootable copy of a Mac OS. The progress bar completes, and an endless white screen appears (just like in the Recover Assistant case). I just can't figure out what has happened, and I'm starting to think that there is an hardware problem. What should I do? Thank you very much for your time!