Pls help! windows XP laptop suddenly shut down & not turning on.

I have an HP dv2130 laptop, with windows xp installed.

I was working on my laptop, while it was being charged. Then suddenly it just turned off, and now
when i try to turn it back on, a black screen appears where it shows the option of entering into setup by pressing F10. Thats it. If I dont press F10, a blank sceeen with just a cursor appears abd aftr about 20 seconds, the laptop turns off again with a beep.

I dont know if its because of this, but I had reinstalled the OS a few months back.

Pls help me! what could be the possible reason?
And what should i do now?

All my data is saved on the laptop, which I really need! I dont even have any backup!