Allright i just bought a new case (Cooler Master 690 ) and a new psu (Antec EA-650 650W ATX12V V2.0 PSU ).

I switched my (kinda old...) motherboard (RC410-M (Asterope)) http://h10025.www1.hp.com/ewfrf/wc [...] 11&lang=en

I've never done that before, by the way. But i often played with computer components

into the new case and plugged psu. I have an nvidia 8600gt as a video card.

Problem is, when i start the computer, everything sounds great. I hear fans (psu is fine then), my usb memory sticks make light (witch makes me think that mobo works?). However, my lcd monitor i get no image. I'm pretty sure videocard works though. I tried to plug monitor into the motherboard video, still nothing.

Monitor gives no signal at all actually, no messages like -no signal-...

I think i just didnt plug something correctly, but i see nothing else to plug on my motherboard... what did i do wrong??

Did you clean the thermal paste off of the old processor and put new paste on and make sure to do it correctly and properly secure the heatsink?

i didnt touch the cpu, it stayed on the mobo when i switched

oh and cpu fan works correctly, too

Emptywords does the lcd have a power light on ever green or yellow?

Some blue light flashing, it does it when the lcd is turned on but comp is off.

I went further to see my problem :

-My lcd works correctly
-My GPU works fine too
-PSU works perfectly
-DVD (IDE) : do not work at all
-Mobo... i don't know...
-CPU : i think that's my problem... the fan on it works. I unplugged the fan and turned on computer and the cpu seemed to do no sound or heat at all... seems like that's whats not working...

I tried to remove ram and put it back in, clear cmos memory, still nothing... so i really guess i got a problem with cpu... is it dead???

I suspect that you have a short with the new case. Take everything out, put the mobo on a piece of cardboard and try to start it up outside of the case with the bare minimum of parts.

How do you know that the psu works perfectly?

... oh well i think cpu (and maybe mobo) is just dead i've been passing all day on it, trying everything and that's the only thing i could conclude. Anyway it's old stuff, gotta buy something new now... thx anyways all