Hmmm I've had a similar problem and it was my RAM.
If you have more than one stick of RAM take both out and try each stick separately (in slot 1 assuming they're labeled) and see if a single stick works. If so, you know that the other stick(s) are dead, if you have more than 2, try them in combinations to see which ones work and what are ones are dead.
If none of them work, perhaps see if a friend will allow you to temporarily cannibalize their laptop to see if the problem truly is RAM or not. No sense in replacing the wrong parts.