Before we start discussing on this, just want to make sure if you checked out the following URL:
Troubleshooting System Boot Issues: http://www.intel.com/support/motherboards/desktop/sb/CS-010254.htm
Now, moving on .. before encountered this problem;
Were you able to power up and shutdown your PC normally?
If so, did you add in any additional components before this sequence of events?
Did your system update any OS patches and if any, were there any pending update installations?
Did you check for the front panel header connections and other cable connections?
Did you experience or noticed any erratic behavior of HDD or memory?
Above asked, they could lead to one of the problems you are encountering since my suspicion is that your PC went into a hibernate or sleep state and won't interrupt signal to power it back on properly which is leading to this very problem.
Either of the above can lead to the resolution of your problem. More importantly, you need to check out the URL I posted above. Let us know how it goes and if you don't encounter any success, feel free to contact us.
Thank you and have a great day!
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