Do you have a VGA port on mobo?
Yes on the thing that sticks out of the side of the case
Do you have a VGA port on mobo?
The PSU supplies power to the fans and such
Have you checked to see your cpu fan is working correctly. the board wont start for safety if the fans not working?
Remove everything except the CPU and CPU cooler... Everything, the cd rom the power the HDD... Everything
Plug in the motherboard power
Add only one stick of RAM
Connect your monitor to the VGA connection
Look for CMOS or BIOS reset, press this or short it using a flat screwdriver
See if it turns on, if it does add one component at a time until it stops
If it doesn't then try second stick of ram