u need to reset the bois and is your cpu in right?
I was told by a tech that the first line of dual core not core 2 had many problems like heat build up and other he didn't go into. But the system started freezing after three months he checked it out and said heat was an issue and dual cores in general had many flaws. Recommended either core 2 or P4.
The reason I posted to begin with is, I changed the processor and when I booted up just black screen.