motherboard is giving no output to my peripherals


what to do if your display is not working, i checked there is no output for my keyboard and monitor please tell me how to resolve it. i cross checked every hardware of my computer . but things not working just in my motherboard. all component working fine in another motherboard. what i have done to resolve it----------

i have ddr2 800 memory module and intel d946gzis mainboard! i have changed memory frequency 533 automatic to 667 user defined( i have done this many times in this computer before). since my computer has not been giving power to my hdd and , no display. all other vital components are running fine.thinges i have tried...........................
change psu with higher power
took out hdd to another pc and it runs fine
checked all data and power cables
checked ram, including rubbing eraser, and replaced with another working ram
took out vga card but still no Display
took out everything and pushed on button for 1 min, than plugged all things
remove cmos batt for 10 min
clear all cmos data via bios jumper
monitor is ok
no sign of burn or overheating in any part of computer

motherboard led is functioning whenever power is on, and makes beep whenever ram or any other vital part is removed from mainboard!
am i missing any thing to troubleshoot it?my monitor is not showing any error message like "check signal cable" but still no display only a blank screen!

i have intel d946gzis genuine motherboard. any solution !
need you help!
If nothings working are you getting beep codes when you try to start the system? Refer to the system manual to translate what they mean.
Try resetting the BIOS settings to their defaults, and make sure all of your hardware ports are enabled. Is the hard drive viewable in the BIOS?

You may need to update your BIOS if a newer version is available.