I just installed a new motherboard to a PC I rebuilt about 2 years ago. I get diddly squat on the screen.....nothing.nada.nil.
Monitor is fine on other machines but the PC doesn't appear to be even in the process of botting up. Would a fried cpu display a blank screen?

"Would a fried cpu display a blank screen?"

Yes. But could be other things. Do you get power? Do the fans work?

Lights? Does the drive spin? Any BEEPS?

Does the processor get warm? HOT?

The monitor doesn't display a 'Signal Not Found' or etc. ?

What is the make & model of the board?

Are you sure that all of the power connections are connected?

To add one more to Jephree's list of questions;

Onboard video or seperate video card?