ATX power supply, 20 vs 24 pin

The AT supply for my Tyan Trinity (Still on a K6-3 like Kieth was, until
recently) failed recently. I decided to try using an ATX supply I had,
but it won't fit gracefully into the box, as the interior fan is on TOP,
and it's a little flakey, and won't start up every time.

I have another ATX supply, and actually ended up using it in a machine
at work for several months when I thought its power supply was acting
up. (The real problem was more sinister, and the machine is now
considered dead, though I still have it in my office.) By the way, that
machine is/was a 600MHz Pentium III, Micron Millenium.

But until I tried to plug that supply into my Trinity, I hadn't noticed
that it had 24 pins. The keying is such that it would plug in to the
Trinity's 20 pin connector, but there's a capacitor there that won't
physically permit it to fully seat.

I've thought about taking my Dremel and cutting the extra 4 pins off.
But before doing that I want to be sure I'm not about to do something
bad to the Trinity because even though keyed alike, the connectors may
not be truly 'superset compatible'. This fear is heightened by the fact
that the colors of the wires on the two connectors are in NO way
matching. I've looked for such things on the web, and found 24 and 20
pin diagrams that look like the superset I need. But the colors on that
diagram are nothing like what's heading into this connector.

But this thing simply plugged into a 2000-era ATX board and simply
worked.

So did somebody bork the wire colors, or is it really a different
standard which I haven't found, yet?

So how much load do I need to put on which pins/voltages, so I can power
the thing up in isolation and check the voltages, pin by pin?

Thanks,
Dale Pontius
(My wife and I are using the kids' computer for the moment, but we need
to get our own back before our son heads off to college.)

On Thu, 01 Jul 2004 20:38:42 -0400 dale.TakeThisOut@edgehp.invalid (Dale Pontius) wrote:
 > But until I tried to plug that supply into my Trinity, I hadn't noticed
 > that it had 24 pins. The keying is such that it would plug in to the
 > Trinity's 20 pin connector, but there's a capacitor there that won't
 > physically permit it to fully seat.
 >
 > So did somebody bork the wire colors, or is it really a different
 > standard which I haven't found, yet?

It's a different standard (EPS12V). 24-pin sockets are typically
used on server-class motherboards.

If you don't mind spending money, there are companies which market
24-pin to 20-pin adapter cables. Go Google. [Though one vendor I
ordered my adapter cable from had the male and female plugs mixed
up - and couldn't understand when I explained their mistake. I
eventually gave up - got the cable I wanted from another vendor.]

mikus<!-- ~MESSAGE_AFTER~ -->