Earlier, I said in the "motherboard 5v" thread:
My $20 power supply is OK with a 12v motherboard. I'll match the K7S5A
with a better power supply.
Once I did, the K7S5A 5v was 4.90 or so. I thought everything was good,
but now, after a few weeks, it's down to 4.80. Still within spec, but if
it keeps dropping, that won't last long. There must something wrong with
the motherboard. A different model motherboard measures 5.01 on the same
power supply.
Before giving up on the board, I searched and found much discussion of
K7S5A hardware problems, and some resistor fixes to make the board run
with an Athlon 1400.
There was somebody named Mr. Athlon who produced a motherboard repair
guide, but ECS threatened to sue people and got them kicked off the web
forum, which is apparently gone now.
With those circumstances and the years gone by, I feared it impossible
to find Mr. Athlon's guide, but I got lucky:
http://www.oocities.org/mrathlon2000/zp.html
In that page, see the "fix guide" link. It worked for me, get it while
it lasts. It's a PDF with pictures, what more can you want.
Looks like soldering fun for me. Sorry if that's not your thing.