PC Powers on, Fans & Hard disk spinning, but no display & beep

I'm not using my pc for months already and so I tried to use it again yesterday. I plugged everything and turn on the PC. It doesn't boot completely so I formatted the hard disk and it boots successfully after the format. I already did windows update and installed everything successfully. After the update it's fine. So I turn it off after using it for a couple of hours. But when I turn it on again after few hours... its not booting, no display, no beep, fans and hard disk working.

I already did clean everything.
Used different ram sticks, cpu fans, power supply, or even processor which is with the same socket and use video card 'cause i guess maybe its just the vga of the board. But none of it works with my old computer. No beep, no display, fans and hard disk working. Those that I used for testing are working in good condition. So I am wondering what's the problem?