I posted to a resolved thread, and i'm not sure if it will be reviewed, so i'm posting this as a new thread.
OK, before I replace the mobo, or cpu, or psu, just a few specifics re my prob. When I shut down the night before prob, everything seemed normal; logging off windows, saving settings, etc; but when I went to power off my monitor, which gave the window that recognized the computer was off, I noticed the power light on my computer was still on. I tried powering off from the power button, even holding it for a few seconds, but it would not power off. So I unplugged it, since the shut down seemed successful.
The next day I plugged it back in, tried to power on, but nothing, zip. I tried disconnecting and reconnecting all power cables to no avail. I swapped out psu's, and immediately upon plugging in, the fan came on prior to my powering up my computer, but the power light was not on, and the amber led light was on. I tried to power up w power button, but nothing. The monitor still showed no signs of computer activity.