System Not Booting After Being Put In Sleep Mode?

I'm running Win 7 Pro 64 bit on a system using an ASUS P5Q Pro motherboard.henever I'm away from the computer for an extended time, I always go to Start and put it in sleep mode. I've never had a problem with it waking back up and resuming until today. I had to leave the house for a while, so placed it in Sleep mode, but then realized I'd forgotten to do something, so before it actually went into sleep mode and shut down, I started moving the mouse to stop it. Nothing happened and I eventually heard the usual pop of the speakers indicating it had shut down into sleep mode. The monitor was blank. I kept moving the mouse, but instead of waking up and going back into Windows, I heard the same beep as heard when rebooting, and the Cmos stuff appeared on the screen as if booting, but then stopped and I saw "Press F2 to load defaults and continue" ....which I did. It started to do something then stopped with no HD activity and nothing on the screen. Nothing.

No activity. I then shut it down using the button on the front of the case and let it sit for a couple minutes. Pressed the On button and heard some activity with the green light and red activity light lighting. Sounded like a normal boot with the beep, speakers popped on, and it looked like something was going to appear on the screen, but....nothing. I could see the monitor had been activated....just nothing displayed. All activity stopped within a few seconds with only the green light still on. The internal fans were running, but nothing happening. Again, I shut it down using the power button, and shut the power supply off as well. I let let it sit and tried again.....same thing. It starts to do something, then quits with just the green light on and the internal fans running. It simply will not boot...and until this episode has been running great.

It seems to have something to do with pressing F2 and loading the bios defaults. I'm wondering if it may be locked in sleep mode. I contacted the guy who builds my systems and is unfortunately out of town and I'm in the middle of a magazine layout. We tried everything, but it simply won't go past that one point. It's not even POSTing. He suggested removing the motherboard battery in order to reset the bios and if it happens to be locked in sleep mode, removing and replacing the battery will delete any sleep mode settings.After reading about similar issues, I removed the motherboard battery and changed the jumper for 10 seconds to reset the bios and finally was able to get into the bios setup.