Paul,
Replacing the capacitors is definitely out of my scope. Now I just need
the
pc to hang in there until I'm done with my project and get a new one. I
hate to think about leaving WinXP since I feel so comfortable with it.
I've
gone thru Win 3.0, 3.11, 95, 98, and XP has been great. I've got a laptop
with Windows Vista and I hate it.
It still baffles me that I can do a hard shut down, and afterwards
sometimes
(not always) movement of the mouse turns the pc back on.
Jack
---------------------------------------------
That is exactly what I was about to ask you next :-( I noticed
the discoloration in this photo.
http://www.leveragegame.com/HPIM7894r-782x585.jpg
The one in the center, with the orange goo on top, looks ripe.
The "lines" on the cap, are stamped in the metal, to form a
pressure relief valve. If the cap starts to fail, and gas builds
up inside, the stamp marks crack open. Then the liquid can ooze
out.
Vcore will be unstable, especially when there are so few output caps
in your circuit, and one of them has failed for sure. It is easy to
get crashes with the caps like that.
I had an ATX power supply that failed like that, and I got some
orange-rust colored deposits on the top of four output side caps.
There are web sites, that sell replacement capacitor kits, but you'd
have to be a died-in-the-wool hardware repair person, to do the repair
yourself.
The thing is, with caps, you have to replace whole sets of them. As
they're likely to fail at the same time. Your Vcore circuit is the typical
two phase design popular with Athlon motherboards. And there don't seem to
be
too many caps associated directly with Vcore.
http://www.badcaps.net/
It would be more "fun" to replace them, if the motherboards were designed
properly for easy removal. At my company, we used extra-large holes for
capacitor
leads, and at the time, it never occurred to me why we used them. Until
one
day, I needed to change out a cap on a board, and it came out easy. A
lot of other boards (like at a second company I worked at), use
"interference
fit" holes, where the leg of the capacitor is basically jammed into the
hole.
Those are the devil to remove. Even with a vacuum de-soldering station, I
had
to say many swear words to get one out. And I had a few of them to do.
With home tools, dealing with that kind of crap, would be no fun at all.
You can take the "brute force" approach, and cut away the cap from the
top,
leaving the spindly two legs standing there. But the problem with using a
lot of force during the repair, is the danger of damaging the plated
holes, ripping up tracks and so on. Motherboards are not fabricated,
with those kinds of forces in mind. If you could get a hold of the lead
from the top, where it goes into the board, you could pull on it while
heating from the solder side, and the leads would come out easier that
way. But man-handling the cap from the top, comes with some risk,
and I've always tried to do them, by removing all the solder from the
holes, and forcing them out from the back.
The plated thru hole, can be ripped right out of the motherboard,
if you use heat and force on them. I know, because I've done that (but
while practicing on surplus circuit boards I used to buy as a kid).
It's how I learned what a plated hole is.
In this picture, you can see a "land" or pad, which may be visible
from the top of the motherboard. In the example, the motherboard
is five layers (which would not be considered normal). Motherboards
are four layer, with two copper layers inside. Some motherboards were
six layer, like RAMBUS boards, as they needed additional controlled
impedance routing layers. There may even be a few with eight layers
for all I know. But since the motherboard cost goes up with layer
count, four layer would be preferred for high volume low cost
computer motherboards. And you can rip that "thing" in the picture,
right out of the hole, with enough force.
http://lh5.ggpht.com/interfacebus.c...Qg/s800/minimum-annular-ring-enternal-pwb.jpg
So now the question would boil down to, is your motherboard make and
model available on Ebay ? And if it is, are the caps on the unit
on Ebay, in any better shape than yours ? The "Capacitor Plague"
affected some computing products, pretty heavily, such that certain
Dell motherboards, you would not expect to find any good ones for
sale (unless someone re-capped them first).
http://en.wikipedia.org/wiki/Capacitor_plague
Paul
