Problems starting SN95G5... red LED???

Hi all,

I am new to the group and new to the world of building PC's. So, please
excuse my lack of experience and knowledge.

So, I put together a Shuttle XPC barebone (SN95G5)... (1)Kingston 512MB
RAM, Athlon 64 3200+, EVGA e-GeForce 6200LE, (2) WD HDD's, and a Sony
DVD-ROM. I tried to power it up tonight after double-checking all the
connections and so-forth. It jumped alive for about a half-second, fans
started, then stopped... there is a red-LED in the rear left-hand
corner of the mobo labeled "LD3" that is on at this point. I am pretty
sure this is not the LED associated w/ AGP voltage (that one is behind
the AGP-slot, right?), but it isn't documented by Shuttle. I also tried
powering it up with no video card, to see if I was mistaken on this,
but it did the same thing.

Does anyone know what this red LED indicates? Any other ideas why it
won't power up?

I also tried re-seating the AGP-card, RAM, and CPU...

Thanks a million for any insight!

Adam S