It may be an idea to double check that the CPU is seated properly and that you havent bent a pin while inserting it along with yet another check that the memory is in properly too,as even without the graphics card you should at least get a post beep when you start it up
Absolutely Sandra. If there are no power on self test beeps, the problem is more fundamental than just a GFX card problem. Although it might just mean that the speaker cable is not installed
I'd be checking that the power and reset cables from the case to the motherboard are connected correctly. As Sandra says, also check that the CPU is correctly installed and there are no bent pins.
Some motherboards have diagnostic LEDs on them. If these are present do they give any clues as to the problem?
Please don't think I'm being patronising, but one thing you might also check is that you haven't mounted the motherboard straight onto the metal backplate of the case instead of using the supplied spacers. I have actually seen this done by a so-called IT Expert who I used to employ
(only I think he spelled it "IT Ecspurt"
)