I've no doubt this is a widespread problem.
I replaced the motherboard in my Dad's computer and know of an IBM server
that had its motherboard replaced under warranty. The symptoms are erratic
lockups or random no boot getting worse with time. Dad's computer was under
warranty but the company would not admit any cap problems and declared that
"electrical surges" voided any warranty. They will never sell to me or him
The caps stick out "like a sore thumb" to anyone who has repaired equipment.
The caps are often obviously bulged with domed tops and occasionally the
case is pushed up off of the base.
An important question is where else besides computer motherboards were these
used? They are of the typical values used for bypass and filtering at 16
volts WVDC and less. I seem to remember values as high as 1000uf to 47uf or
so. I don't recall the capacitor brand.
From: firstname.lastname@example.org [mailto:email@example.com]On
Behalf Of John T. M. Lyles
Sent: Wednesday, January 14, 2004 10:13 AM
Subject: [Amps] bad electrolytic capacitors
Heard about this on the AM forum:
In the conservative news forum free republic:
The conmpanies mentioned included Teapo Electronic Corp, Jackcpn
Capacitor Electronics Co. Lelon Electronics Corp, and Luxon
Electronics. None of which I have ever seen in the larger varieties
of capacitors which might be used in a typical voltage multiplier SSB
low duty factor HV power supply.
Referenced in the article is an IEEE Spectrum article from last
February, abstract shown below:
>Leaking capacitors muck up motherboards
>Yu-Tzu, Chiu; Moore, S.K.
>keywords: Aluminum; Electrolytic capacitors; Printed circuits;
>Failure analysis; Microcomputers; Al electrolytic capacitors;
>Motherboard failures; Desktop PCs; Low equivalent series resistance;
>ABIT Computer Corporation; Faulty electrolyte; Burst capacitors;
>Intellectual property theft
Abstract (English): Aluminum electrolytic capacitors with a low
equivalent series resistance (ESR) are high-capacitance components
that generally serve to smooth out the power supply to chips.
Throughout 2002, they have been breaking open and failing in certain
desktop PCs. So far, the only motherboard maker to admit to the
problem is ABIT Computer Corp. (Taipei), and the only major PC maker
to acknowledge being affected is IBM Corp. But the problem is likely
to be more widespread. It is clear now that a faulty electrolyte is
to blame for the burst capacitors. Apparently, a scientist stole the
formula for an electrolyte from his employer in Japan and began using
it himself at the Chinese branch of a Taiwanese electrolyte
manufacturer. He or his colleagues then sold the formula to an
electrolyte maker in Taiwan, which began producing it for Taiwanese
and possibly other capacitor firms. Unfortunately, the formula as
sold was incomplete.
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