No display, beep code or boot after Sleep Mode

Hi,

I've seen like a million other threads for this particular problem with just about every kind of possible solution there could be. However, as no two computers can be identical, I'd give it a shot and get some help on this one.

After attempting to resume Win7 from Sleep, none of my displays awoke so I shut the system down, checked all cables and leads for the monitors. As it were, no issues.

I booted my PC to be presented with a whole lot of ... Nothing. All drives and fans were functioning, my DVDROM did it's little check for CDs, all the normal crap, only it neither woke up, or brought me to GRUB.

Thus far, I've reset CMOS, done bare bones booting, tried my GPU, HDDs and PSU in my several other self built machines. No problems, no drama.

I'm yet to test my CPU and RAM in another machine, as I don't actually have another capable of it at present. I'm also quite unsure on whether my speakers works or no, I've tried several with no beep codes.

As of right now, it's still set up for bare bones booting. I should also mention that the power button needs to be held to kill the system on an attempted boot.

Any ideas, or help would be appreciated, specs will be posted below.

Cheers for the assistance.

OS: Windows 7 Ultimate 32bit & Fedora 11
PSU: Ritmo Force680
CPU: Intel Dual-Core 2.7Ghz E5400
MOBO: Asus P5G41T-M LX
RAM: 2x Kingston 2GB DDR3 - KVR1066D3N7/2G
HDDs: Seagate Barracuda 40GB - ST340014AS
Western Digital 500GB - WD5000AAKB
GPU: ECS GT220
(alternative: MSI N9500GT)

EDIT1: Any suggestion would help, including "try hitting it with a sledgehammer" as a valid idea.

Could it be possible the BIOS is damaged or corrupted from a failed wake up?

EDIT2: Strange. Just tried to boot it to find that there is an odd problem. First attempted boot it took around 5 seconds for the PC to start. Once it did, it powered off and back on again. Second attempt, it took around 15 seconds to boot, this time with no powering off and on.

It would appear the PSU might be the culprit. (I also noticed the PSU fan took a little to get going after power up.) Going to retest the PSU in an another machine and will edit with results.

SUB-EDIT2: PSU continues to function normally in other systems. So what could be the possible culprit? It would appear to be either a mobo or a CPU problem. Unsure on if there could be much else. Require input on this.

EDIT3: As it so happens... It seems to be booting successfully now. I've put all hardware, cables and leads back to their original locations and it boots, or so I assume. The activity indicator now does it's job when the PC is booted, and my reset button works once again. I still require to hold the power button to kill my system, but I believe that is due to ASUS TurboKey (Makes power button auto overclock PC on-the-fly). Displays still don't function. Going to attempt my alternative GPU and will re-edit with results. USB mouse and keyboard also appear to not function, which is normal at certain stages of my boot up. The only times they function during boot is at BIOS, GRUB and once I've launched my OS. Still, could be a potential problem indicator.

EDIT4: No change. Main, alternative and onboard, it doesn't matter what, it doesn't display anything.

EDIT5: The CPU and RAM are fully functioning in another system, it would appear either the BIOS isn't receiving the power up signal or it's damaged/corrupted. Unfortunately, I cannot flash the BIOS or restore it. Problem solved.. Sort of. Going to replace it, but keep it incase either myself or someone else stumbles upon a possible solution. I'd like to request this thread stays open incase anyone has ideas, or I find the solution so it can be archived at least. Thanks for, well, allowing me to brain storm.

Any help and ideas would still be appreciated.

(I apologize for the double post, but for some reasons I'm now unable to edit my original - if a Mod can merge or edit, please feel free to do so)