I'm not an expert but it sounds like a motherboard issue. I would try calling asus in the morning - they're extremely helpful and they'll troubleshoot the board with you. At least then you'll know what you're dealing with. Here's the contact numbers:http://support.asus.com/Hotlines.aspx?SLanguage=en
Also try to find out exactly which light is lit on the motherboard - the manual should help you with that. My asus z68 board has a boot_drive light that stays on until it finds something that it can boot from and when there's no OS the light just stays on. If that's the light that's on then maybe everything is working properly except that your video card is faulty and can't display anything, although that wouldn't explain the fan issues.