System not booting after being put in sleep mode....won't post

I'm running Win 7 Pro 64 bit on a system using an ASUS P5Q Pro motherboard. Whenever 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. I went through and changed some things but still didn't help. Still won't boot or post.

Any ideas?
DC

Yes, the HD is correctly detected in the bios setup, along with the two DVD drives. So it's seeing the HD and I'm not getting any audible/visible errors. Since I am hearing the single beep at startup, I'm guessing it is in fact posting. But it stops after the post beep with a blank screen and only the green light visible on the front of the case.

I attempted to run the Win7 repair utility by setting the boot sequence to boot from the DVD drive, but stops before it gets that far, so doesn't work. Also tried f8 on startup, but doesn't work. It simply will not get past the post beep.

Here's what I've also done:
1) Removed both 2GB mem sticks, powered on and got successive 1-short & 3 long beeps
2) Unhooked all peripheral components except monitor and mouse
3) Tried powering on with one mem stick at a time
4) Swapped mem stick locations
5) Checked all mobo connections/cables
6) Reseated connections

Only thing I haven't done is check the PSU (Antec EA500D) since I have no way of doing it.

Really don't know what else to do. And I'm a graphic designer in the middle of a major magazine layout. All client files are on an external drive, so are safe. But since I can't access the programs I use....InDesign, Photoshop, Illustrator, etc from my main system (the one with the problem), I'm dead in the water.

That's why I showed you how to boot Win7 on different hardware in another PC.

I'd swap in another PSU to see if it makes a difference. The mobo seems to be alive since it's generating the beep codes correctly.

Do you get a signal to the monitor? Try booting the DVD ISO written to flash stick using tool in Step 5 of tutorial provided. If it fails the unplug the DVD drive to see if it's interfering.

Another update.

I hooked up the main DVD drive and tried booting again after doing the battery/jumper thing and was able to boot into Windows after pressing F2 to load defaults....and at least have been able get some work done. I updated date/time using Control Panel.

My friend who has been out of town is back (the one who built the system), and while talking by phone today, he suggested updating the ASUS bios using the CD that came with the board. It's more than five years old, but I eventually found the CD and was able to download the latest update and get the bios updated/flashed. It required a reboot, and for the first time since this "adventure" began, it went past the beep and made it to the AMI bios screen without having to do the battery/jumper thing, although I did have to press f2 to load defaults. And the time/date was correct since the battery wasn't removed. So updating the bios made a big difference and seems to be doing fine. I have work to get done, so haven't tried rebooting from this point yet to see if it'll go through the whole sequence w/o having to press f2. But hopefully the bios update has fixed it.

Why would your builder expect that a five year old driver disk would have the latest BIOS update? Check the Asus Support Downloads webpage for the model.

I should have been more clear. When he suggested updating, he told me I can either go direct to the ASUS site and go through the process of entering info to locate my board and updates...or simply use the disk which automatically searches my system for the current version, then connects with the ASUS site to search for updates for my particular board. That's exactly what it did and couldn't have been easier....and I now have the most current version.

Still experiencing the same problem, my friend who built the system finally got a chance to look at it, and after running several tests, discovered the cable connected to the HD was failing. He replaced the cable, and no more problems. Mobo, processor, PSU, memory all checked out fine.