I like using my laptop with better display. It's irritating if the screen has problem.
There are multiple causes for this.
First check whether there are any lights glowing on the keyboard or not, The caps lock and Num lock LED might be blinking and if yes, what is the sequence?
Is it blinking once, twice, thrice or more....??
Try these step first:
Unplug the AC Adapter and remove the battery.
When there is no power source to the notebook, press and hold the power button for atleast 40 seconds....
Then connect only the AC adapter and try to turn on the notebook.
If the issue is because of static electricity, it will be fixed by doing this.
If not, you need to remove and reseat the memory module and harddrive.
If your notebook is inwarranty, better contact HP phone support at 1800-474-6836.
If its Out of warranty, try chat support...