My son's Asus K55N went through the same throes and in the end it was a failing HDD.
Luckily I had cloned the drive long ago so I could slip that clone drive in for a test. That test passed so a little more discovery about the ASUS BACKTRACK APP to create a true restore USB stick. Now I could slip in a new HDD (cost 55 bucks for 500GB) and restore it to factory condition.
The old failed drive was another Seagate so it went into some USB case for my son to copy their files out. (OS blown, user files were accessible.)
Note: Corrected spelling error.
My 3 year old ASUS N56 won't completely reboot and I think it might have crashed.
I recently downloaded Steam and was installing my first game (about 3.5GB). The download went fine and I had the box checked to automatically start the game when the installation was complete. As soon as it was finished, my computer shut down and said it was restarting, however it never fully restarted
Eventually I got a notification first saying "Preparing Automatic Repair", then "Diagnosing Your Repair", and then "Repairing disk errors. This might take over an hour to complete". After the computer seemed to be done, it shut off and then went to reboot again. Now all I get is a loop of the ASUS logo on a black screen for a minute or so, then the computer shuts off, seemingly trying to reboot, and then gives me the ASUS logo on a black screen again. There is also no noise that sounds like my hard drive is trying to boot and no text or symbol below the logo such as a throbber.
I spoke with ASUS customer service, who's only advice was to try to restore the computer through the F9 key. This had no results. The only response I can get is by pressing the Esc key to bring up the boot options.
I wonder if it would help to reboot through a USB? Or maybe my hard drive crashed due to the game download? I would like to avoid shipping it in to ASUS and risking a costly repair. Any help would be very much appreciated.

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