Ok, wierd set of symptoms for what turned out to be a power supply issue. After swapping around the CPU's and memory, double checking the heatsink clips weren't shorting the board, re-seating all the connections, and removing all non-essential components, changing the power supply fixed the problem. My (false) assumption was that if the supply goes bad, the CPU fans wouldn't run and I wouldn't get any response from pressing the power button. I guess that's not true. During the course of this, I've learned a couple of things:

1) I personally have about a 1 in three chance of having an Antec power supply fail (I've used 10 in the past 6 years and three have died prematurely).

2) That black plastic gasket looking thingy that came with the Z7S is actually a template to properly locate the heatsink plates in an ATX chassis. (The small holes slip over the standard ATX mounting standoffs, and the cutouts are perfectly placed and sized for the plates.) No more figuring out to mount the board with the plates pre-attached! (I'm hoping I didn't miss that info from a previous post. )

3) Asus at least has the wisdom to ship new mobo's with the latest bios (mine came with 0302)

4) The stock Intel heatsink / fan combo is FRIGGIN LOUD!!!! My 12 year old POS vacuum is quieter than the two of these at full tilt. My wife won't let me bring this rig in from the garage until they are replaced with something quiet. That's what you call a justifiable expense.

5) A failed or failing power supply will frequently create the most frustrating and confounding troubleshooting.

On to happier subjects. Here is the link mentioning the 0401 bios:

http://support.asus.com/cpusupport/c...model=Z7S%20WS

Like I said before, the 0401 link just leads to the 0302 listing, but someone with a reliable contact at Asus ( ) could call them and get an ETA.

Thanks for listening and posting. I'm off to battle the SSD's. Rumor has it I'm in for some pain with these.