Freezing laptop

Hello,

I have a hi-grade VA250P. whenever i turned it on the power and the wi-fi light come on and the fan just spins. i moved a card (not sure what card it is) into the slot above and now the laptop works. but after 5 mins it freezes. and no-matter what i do the same things keeps happineng. iv even took the whole thing apart and cleaned it all. and still same thing. is there anything i can do to fix it????

many thanx dan