Computer won't start after Hibernation (sometimes)

[Nasroo7]

Hello everyone!
I hope that you are having a nice day, and that you had good holidays!
I have an issue with a laptop: HP Pavilion dv4-2154ca running Windows 7 Home Premium 64x
AV: Microsoft Security Essentials.
I did a Windows Recovery using the built-in recovery partition back in November 2013.
I updated Windows using "Windows Updates" (Until it said no more updates), and no other software.
I have no driver software updater or anything like that.

The computer works great, except that sometimes after leaving it ON for a few hours, it will put itself in Sleep mode, and then in Hibernate mode. So far, so good.
However, when I come back to turn it back ON, it won't turn ON 10% of the time.

The screen stays BLACK (Like there is no signal to the LCD) [No blinking cursor...]
Other times, It shows the BIOS logo, then "Resuming Windows". Then Black Screen.

All lights are ON, and the Fan is running.
I have to press and hold the power button to turn it OFF, and then turn it back ON in order for it to work.
But it happens only sometimes. Not all the times.

Do you have any ideas?
Is it some kind of a Hardware issue? Or maybe power management drivers... or graphic drivers?
I thought maybe I post the SF Diagnostic Tool and see if anyone could help me with it.

Also, it doesn't give me a BSOD, and it doesn't restart by itself... But I didn't know in what section I should post this. So, if It's in the wrong section, please let me know, and I will change it.

THank you for your help
And have a great day!

 

[Slartybart]

Try toggling hibernation, sometimes the file collects garbage.

Turn hibernation off
restart
turn hibernation on
restart

see: http://www.sevenforums.com/tutorials/819-hibernate-enable-disable.html

if the problem persists after another sleep cycle then that obviously wasn't what caused the issue.

 

[Nasroo7]

Really?
Okay, I'll try, and post back.
Thank you!