Okay, I'm desperate for some help before I declare my new motherboard
DOA and call Asus. Here's the deal:

1. A few days ago, we had a horrible storm. I unplugged my old MB,
but apparently too late: the system wouldn't boot. No CPU fan, no
power supply fan, no nothing. I swapped the MB/CPU/RAM with another
box, and it booted fine, so the power supply appears to still be good.
When I put my old MB back in, the CPU fan came on for a few seconds
as soon as the power supply was switched on (without hitting the case
power switch), then went off. The standby light on the MB was lit,
but nothing happened when I hit the case power switch. Same as
before, no fans or anything.

2. Planning on upgrading soon anyway, I went ahead and ordered a new
MB/CPU/RAM (Asus A7N8X-X with Athlon XP 3200+ and 1 GB of RAM). Lo
and behold, I installed it in my old case, and got the exact same
problem: CPU fan spinning up when the power supply is first turned on
(which I assume is a self-test), but nothing when I hit the case
switch. To rule out a problem with the case or PS, I stuck in another
old MB, and it booted fine.

3. Since then, I've tried everything I can think of: I've tried
reseating the CPU, RAM, and heat sink. I've reapplied the thermal
paste. I've made sure the CPU fan is plugged in the right place.
I've checked the CPU for bent pins. I've checked and double-checked
the orientation of the ATX power switch connector to the MB's control
panel. I've made sure the power supply connector is seated firmly.
I've cleared the CMOS. I've tried it with RAM, without RAM, with
video card, without video card, with HD's connected, etc. I tried it
with a different CPU and a different heatsink/fan. I even tried it
with a different power supply, new out of the box. I tried reseating
the MB to make sure there wasn't a short somewhere, and even hooked it
up sitting on an anti-static bag to make extra sure. Still no
activity at all when I hit the case power switch. The standby light
on the MB is always lit when it should be, but nothing happens at all.

Am I missing anything obvious? Any other suggestions before I box the
thing up and send it back?

Thanks,
Jeremy