Symptoms: PC turns on, fans spin up, computer appears to boot into windows, but there is no video output. Monitor is dim with an amber power light, apparently getting no signal.
Hardware: In signature.
Troubleshooting: Occasionally during troubleshooting, the 8800 GTS / P5K would boot up with video. The 8800 GTS video card works fine in other PC. Other PCIE video cards work fine in the P5K board. Plugged a speaker into the P5K board and the BIOS error code beeped LSSS, indicating the obvious - it could not find a VGA adapter.
Resolution: When the 8800 GTS was seated firmly in the PCIE slot and both screws bolted it securely onto the case, the board could not see it. When the 8800 GTS was seated more loosely in the PCIE slot and not completely bolted down, it worked fine. The card isn't going anywhere. It's screwed onto the case, but it's not pushed ALL the way in.
This was the result of several days of hair-pulling frustration - swapping hardware, reseating everything, taking the computer apart and putting it back together, updating the mobo BIOS, updating the video card BIOS, sacrificing chickens, etc. I found posts from other puzzled users on a variety of forums with similar hardware and the same problem and none of them appeared to have found a resolution. Or, if they did, they didn't share.
Hopefully this information will come in handy for someone in the future.
Asus P5K Deluxe
ULTRA 550W X2- Power Supply - Titanium