[lug] hardware question

[bgiles at coyotesong.com]

Quick hardware question.  I just swapped out my hard disk and had no
problem installing Debian and doing some initial setup while the disk was
resting on the floor.  I shut down the system, moved the disk into its
holder, and hit the switch in the back.

Now the system isn't booting.  The fans spin up but then immediately spin
down.  My first thought was that one of the cables had brushed against
something, but that doesn't seem to be the case?

Any ideas before I make a trek to get a new motherboard or barebones
system?  I have a growing fear that somebody cut corners and that wasn't a
hard switch.