This old computer I have came with a Core2Duo 1.8 dual core chip. I got a 2.8 for $4 on ebay and popped it in today. The computer powers on, but nothing happens on either of my monitors, one a DVI and one a VGA. The DVI fed one comes off the GPU, the VGA is straight off the MOBO. I've heard that some HPs MOBOs won't accept a new chip, but I at least expected the BIOS or something. What am I missing here?