Dude, make sure the mboard is totally flat and all reverse solder pins never touch the backplate. Never tighten the mboard screws too tight either.
Check your mboard manual for troubleshooting error codes/lights.
Chuck your os cd in the drive, press your bios key, usually 'del', order boot to cd first, save and restart.
When I press Del nothing shows up on the screen. Also I made sure nothing is touching the case and all skrews and good. I don't know if I over tightened but I don't it:( When I try to press del on boot nothing shows up. The screen remains blank.