Dear sir/madam,
Thank you for contacting ASUS Customer Service.
My name is Penny. It's my pleasure to help you with your problem.
Do you have another power supply to change and have a test? If the system still can not boot up normally, please take all your ram sticks out from motherboard, and power on. Will it give you long-long-long repeat beep warning? If so, please clean your ram connectors with alcohol or with a clean rubber then install your ram sticks back, you can first install 1 stick of ram, if the system can boot with 1 ram stick, add another. If the system still can't boot up with those ram sticks, please change another ram stick to use and boot up the system to test.
After above steps if the system does not boot and give no beeps, please take out your! VGA card, power on, will it give you 1 long and 2 or 3 short beeps followed? if so, please try to clean your VGA card connector and install it back to motherboard, or you can try to use another VGA card test again.
If the above steps are all not helpful, I think maybe your motherboard or your CPU is faulty, you need contact with the dealer to take a future test for each one and make sure on earth which part causes system won't boot.
If you have any problem, please refer FAQ(Frequently Asked Questions) or contact us again. We will try our best to help you.
http://support.asus.com/faq/faq.aspx?SLanguage=en-us