Start with the basics - remove memory and video. Double check all power.
Add one stick of memory - and boot. listen for beep patterns. Shutdown.
add video - and boot. See what is displayed if anything.
Report back.
The theory here is something is not connected right - and an error beep pattern is coming up. This pattern means something - so you could lookup with ASUS or read the manual to find out what it means.
good luck.