> Thanks for clearing this out for me. I still have not got it to work
> though - the PSU does not power up when I try to switch it on.  I
> have checked the connections, (after getting a multimeter), so my
> suspicion is that it could have something to do with the PS_ON and/or
> PWR_OK connectors.

Have you verified that the PSU powers up OK on its own?  ATX supplies
are, in my experience at least, generally willing to power up with zero
load; just ground the "please power on" line.  (This, again in my
experience, is a green wire going to the 2x10 connector, in the middle
of a bunch of grounds (black) on one side.  It is a lighter (thinner)
wire than most of the wires to that connector.)  Conveniently, there
are a bunch of grounds right next to it, so just a piece of wire bent
to fit between two adjacent pins should do the trick.  Always has for
me, at any rate. :)

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