Something wrong with my new build

[topsnakebite]

i bought my new build around month ago and i still cant figure it out.There are 3 red lights on the back of my 4870 1gig and there is no signal comming up on my screen
mobo is asus
psu is ozc 600watt please help ty

 

[Proximon]

http://www.tomshardware.com/forum/261145-31-build-post-checklist

There is a good place to start.