i'm in need of some techie insight...

ever since i put together my current desktop pc (i know enough about computers to have done that a few times) it has behaved strangely during bootup. when i push the power button the lights inside the case come on and hard drives start spinning, etc, but nothing shows up on the screen. no POST, no nothin. then after a delay (sometimes 1 second, sometimes 20 minutes), with no intervention on my part, the power appears to go away (lights off, no noise) and then comes back and everything starts up normally.

i have no clue why my pc seems to do this 'false start' every time i power it on, and it makes me never want to turn it off since sometimes it takes forever to hit the point where it is actually booting up.

any ideas? everything works fine once this hiccup is passed...