Hangs at Startup

[TurboNitroMonkey]

Ok, I don't know if this is the right place or the worst case scenario. This may not be particularly a vista issue at all, but the people here in the past seem fairly knowledgeable.

The problem:

Computer worked perfectly <12 hours ago, clean shutdown.

Then, 1 hour ago:

Computer booted to blue screen memory dump, reset, booted to Asus Striker Extreme splash screen, hangs, keyboard lights do not light, (they did during blue screen memory dump) but the tab and delete commands do (briefly) (sortof) work anyways.

Now:

Boots to Mobo splash screen, same keyboard light issues, but if tab is keyed during splash, it will change to Phoenix - AwardBIOS v6.00PG screen which I assume is the BIOS post screen, having never had to go to it before. The computer becomes completely unresponsive at this point.

If del is keyed during splash, the message at the bottom is replaced with "Entering Setup....."
The computer becomes completely unresponsive at this point.

If I don't key tab or delete IMMEDIATELY and repeatedly when the Striker Extreme Republic of Gamers logo splash, neither will do anything and the computer will become completely unresponsive.

The difference between this, I think, and some of the other issues is that my computer has worked (effectively) flawlessly for about a year now.

THE CAVEATS:

The LCD post screen on the motherboard is somehow flawed, and now only displays faint (but changing during startup) gibberish.

My system is water cooled, so disassembly is very very difficult, and a last resort.

THEREFORE:
I don't even know if this is a CPU-INIT issue.
But my research suggests this is a good place to start, and this forum appears to be populated by knowledgeable people.

My System:
Asus Striker Extreme
P4 Quad 2.4
Dual 8800GTS 640mb in SLI
SB Extreme Gamer Audio
4gb Corsair RAM (I forget the specs, but it obviously works)
72GB 10k SATA HDD
500GB SATA HDD
1TB SATA HDD
Pair of CD/DVD-RWs

Audio Cards and Processor are h2o cooled on 2 separate circuits, and there is a lot of tubing in my case, so any solution that favors not ahving to remove hardware, specifically those three pieces, or the motherboard as a whole, will be highly favored.

Thoughts? Opinions? Suggestions? (I'm a fairly talented computer guy, and I'm stumped with a $3k paperweight. Please help.)

-TurboNitroMonkey