Hi there wotanwolf
Not sure what really the problem is. But maybe I can help with these basic steps (sometimes i forgot these things myself):
1. Maybe re-check the pin setting especially for the power switch in the computer case
2. Confirm if you have plugged in the 4-pin fan heatsink cable to the Board connector named CPU-FAN or just the socket near your processor (not the 20+4 ATX Power supply connector). As this gives power to the heatsink
The green light on the board indicates a special feature of the Intel Desktop board (not sure what it is called really, but I know it's not for power indication. Yet, it is still a good indicator that power is supplied through your board, Sorry for confusion)
Also, check this page out for your board. Just an overview for installing. http://www.intel.com/support/motherboards/desktop/sb/CS-020836.htm
I wish I could be some help through these simple informations.
Hmm.. So that didn't work
Have you tried isolating the components? Unplugging all the devices except those that are essential
Try to boot up with just the board, processor, memory and power supply plugged in
If you have more than 1 stick of RAM, try booting up with either of the memory sticks
Maybe you can also try different components on your system
Also tried looking up on different forums and all that comes up is checking of each different components
Hope this helps..
Just to add up to that,
Try testing the power supply externally
Or bypass the computer case power switch and manually power on the board (Faulty computer case power switch, maybe unusual, but it still is possible)
On the Motherboard, locate the pins for the computer case power switch and remove the caps over them
there should be two pins exposed. short them with a flat-head screwdriver and see if the system turns on
proceed with caution thinkering with your system while the power is plugged in
I have had that same problem several times over the years of building computers. I would suggest trouble shooting by:
1) Check all connections especially the switch and front panel lights on the front panel connector.
2) Pull all of the parts out and insert one at a time. Use the internal video even if you intend to use a video card.
3) Remove the CPU and inspect to make sure of orientation and damage. If you have an old CPU try it in to see if it works.
4) If you have a working system, you can try each of the components including the CPU to make sure they are not damaged.
5) Pull the motherboard and make sure there are no metal standoffs that may be in the wrong case holes and shorting the circuit board.
6) Be a detective eliminating each part of the system one by one.