TriggerFinger

So you did not put thermal paste? I suggest even for testing, apply the thermal compound to prevent damage to your cpu. Thermal paste is only $10 a tube at RadioShack but a CPU costs more.

If you are sure about the RAM, then may be it's the video or the mobo. A more expensive fix than just replacing the RAM.

Have you tried to reset the system? If not, remove the battery and unplug AC. Press and hold power ON button for 30 secs atleast. Plug back battery and ac adapter. Power ON as normal.