Do you get beeps pressuming the internal speaker is connected, that should tell you what isn't working.
It is possible it is the graphics card, I have had one that was dead on arrival. The only problem is theres so many different things that could be wrong and without being able to swap over different parts the beep codes are what you are stuck with.
I would suspect either its the power supply or the graphics card. I don't suppose it has onboard graphics does it, if so you could try that?
I presume also that you have connected any extra power connections both to the motherboard and also to the graphics card?