is the motherboard green led light on ? can you get into the bios ?
if nothing run through the motherboard setup use in the manual, check cpu fan is connected, & the 4 pin atx12v header are correctly plugged in (top left of mobo)etc.
Asus q connector has the power switch (pwr sw) is it plugged in?
do you get any beeps?
note: 1 long + 3 short beeps no vga detected.
try a bios (clrtc)reset
all the usual suspects to try 1st.