I had a problem I thought was from an electrolytic. But, I finally
discovered that it was caused by the substance used to attach an
electrolytic to the motherboard when the factory chose to correct a design
defect with a supplemental capacitor "glued" to the motherboard. The
"glue" shorted out the circuit board wherever it contacted it. It was on a
ham rig.
73, Colin K7FM
> [Original Message]
> From: Patrick A. Thompson Sr. <wa4tukhr@comcast.net>
> To: John T. M. Lyles <jtml@lanl.gov>; <amps@contesting.com>
> Date: 1/16/2004 1:07:35 PM
> Subject: RE: [Amps] bad electrolytic capacitors
>
> 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
> again.
>
> 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.
>
> Pat
> wa4tuk
>
> -----Original Message-----
> From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com]On
> Behalf Of John T. M. Lyles
> Sent: Wednesday, January 14, 2004 10:13 AM
> To: amps@contesting.com
> Subject: [Amps] bad electrolytic capacitors
>
>
> Heard about this on the AM forum:
> In the conservative news forum free republic:
> http://www.freerepublic.com/focus/f-news/849190/posts
>
> 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.
> Publisher: IEEE
>
> 73
> John
> K5PRO
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