New power supply wont power motherboard compac

Here is the layout for your motherboard

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00......







hope that helps

thank u so much-i guess what i really need to know is-what didnt i connect right that would power supply and cpu lights but not cpu? disk drives start but no hard drive or board fans? new ps has power switch n back-not old---would it make difference?

Look at the 4 pin white power socket top, between the CPU socket and the top left screw hole, it needs plugged in.