[Solved] No display problem

Recently I finished putting together my new PC.
After a few minor problems with getting everything running, it starts.

But when I go to hook the PC up to my monitor, and turn the PC on, nothing happens.
I've tried using both VGA and DVI cables, I've tried hooking it up through my motherboard's connectors, and graphics card.

I don't know why it won't work.

I have a MA790GP-ud4h motherboard, and a Sapphire HD 4870 Vapor-X 1GB graphics card.
This is a completely new PC, nothing is even on the HDD.

Any reason as to why a signal might not be getting detected?
Also, on the graphics card is a red light that lights up every so often, I'm not sure if that's bad or not, but it happens.

Sorry if this is in the incorrect category, it seemed to fit a display problem.

I a having the exact same problem! I finished building about an hour ago, everything seemed fine but I turn on the pc and the moniter stays on standby!

also the computer seems to powerdown after about 3 mins and im really worried I could be having power issues