No boot, screen, beep on startup

Hi am i having problems or what! Hope somone can help.

I'm running windows 7 rc whic ends today and will start to shutdown tomorrow i think as it said i had one day left. Anyway i have already backed everything up ready to install full version.

Today i was just checking emails briefly and making sure everything was good for custom install. Anyway went away and as walked into office computer clicked off and i thought it had shutdown! Tried to restart nothing. Turned psu off and then tried starting lights and fans come on briefly about a second and then goes off. Thought maybe this was windows 7 rc at first but obviously not and just coincidence.

Okay. Have removed everything except for following. Cpu and fan, memory, graphics card and monitor. powerswitch and speaker. Have tested psu and all appears good. 3v 5v 12volts etc.

When booting al starts i.e fan etc come on and phase lights on motherboard all come on. then thats it nothing else. no beep or screen bios etc?

i can turn computer off with power switch still and then power back up again. but still all dead! So not sure if motherboard or processor.

Less than 12 months old self build. until now all has been good even with windows 7 rc working!

Any help ideas most appreciated as pulling my hair out

motherboard: gigabyte GA-EP45-UD3R
VGA: Gigabyte HD4550
CPU: intel q8200
Memory: corsair 4x 1GB speed 800
PSU: coolermaster 450W
Drives: 180gb 200gb 1Tb all sata
OS: windows 7 RC

 

Test your video, replace it by video from another machine temporarily.
Second test is power supply.
If both goes well - your choice is to replace motherboard.

 

You could also try changing the RAM modules in the slots. They could be matched in pairs and the slots will be colour coded. Try using one pair at a time.

Read in the motherboard manual about using the Clear CMOS jumper.