Presario C714NR Vista Home Premium Laptop

[ideas]

Whenever it goes into hibernation and i press the power button to wake, nothing happens it just stays in a black screen

or sometimes it just freezes shortly after i power on. no error message, no blue screen, no beeping sound. It just freezes,

can't ALT CTRL DEL or if i press the power button once nothing happens, i just have to hold down the power button for at

least 10 seconds for it to power off.

can someone help?