They were defective in manufacturing. The Antec I had that failed in
that way, had very low service hours on it. It just has to sit for a
couple years, for the "rust" color to show up.
"A major cause of the plague of faulty capacitors was industrial espionage
in connection with the theft of an electrolyte formula. A researcher is
suspected of having taken, when moving from Japan to Taiwan, the secret
chemical composition of a new low-resistance, inexpensive, water-containing
electrolyte. The researcher subsequently tried to imitate this electrolyte
formula in Taiwan, to undersell the pricing of the Japanese manufacturers.
However, the secret formula had apparently been copied incompletely, and
it lacked important proprietary ingredients which were essential to the
long-term stability of the capacitors."
"With capacitors in which the internal pressure build-up was so great that
the capacitor case was already bulging but the vent had not opened yet,
then the pH value of the electrolyte could be measured. The electrolyte
of the faulty Taiwanese capacitors was alkaline with pH (7 < pH <8).
Comparable Japanese capacitors on the other hand had an electrolyte with
a pH in the acidic range (pH ~ 4)."
http://en.wikipedia.org/wiki/Capacitor_plague
One motherboard company, had a class action lawsuit raised against it, in
order for the customers to get support for the bad caps on their motherboard.
And Dell had some trouble with particular computer models, where the failure
rate of motherboards was extremely high (almost guaranteed to go bad). I think
even IBM had equipment with the bad stuff in it. Not all companies were
affected to the same extent (as their purchasing habits differ).
And upon knowing that odds were good that Japanese products were not affected,
some got in the business of making capacitors with name brand Japanese labeling.
So counterfeiting was also a problem. So even if an electronics manufacturer
"tries to do the right thing", a purchasing agent could acquire counterfeits
instead of the real item.
Paul
