Capacitor plague: Difference between revisions

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{{Short description|Period of high failure rate of capacitors}}

[[Image:Bad_Capacitor_01.jpg|thumbnail|right|Leaking Chhsi capacitors on a MSI 694D Pro [[motherboard]].]]'''Capacitor plague''' (also known as '''Bad Capacitors''' or '''BadCaps''' ) is an informal term used to reference the common premature failure of certain brands of [[electrolytic capacitor]]s used on some [[PC motherboard|motherboard]]s, video cards, and power supplies.

{{Use dmy dates|date=December 2020}}

[[File:Al-Elko-bad-caps-Wiki-07-02-17.jpg|thumb|right|Failed aluminium electrolytic capacitors with open vents in the top of the can, and visible dried electrolyte residue (reddish-brown color)]]

The '''capacitor plague''' was a problem related to a higher-than-expected failure rate of non-solid [[aluminium electrolytic capacitor]]s between 1999 and 2007, especially those from some Taiwanese manufacturers,<ref name= Paumanok>{{cite journal |author=D. M. Zogbi|publisher=Paumanok Publications|journal=Passive Component Industry|url=http://old.passivecomponentmagazine.com/files/archives/2002/PCI_02_05Sept-Oct.pdf|volume=4|number=5|date=September 2002|title=Low-ESR Aluminium Electrolytic Failures Linked to Taiwanese Raw Material Problems|pages=10, 12, 31|archive-url=https://web.archive.org/web/20160303234525/http://old.passivecomponentmagazine.com/files/archives/2002/PCI_02_05Sept-Oct.pdf|archive-date=2016-03-03|access-date=2018-06-15}}</ref><ref name=PCTools>[https://web.archive.org/web/20171009174242/http://www.pctools.com/security-news/faulty-capacitors/ The Capacitor Plague, Posted on 26 November 2010 by PC Tools]</ref> due to faulty [[electrolyte]] composition that caused [[corrosion]] accompanied by gas generation; this often resulted in rupturing of the case of the capacitor from the build-up of [[pressure]].

An incorrect electrolyte formula within a faulty capacitor causes the production of [[hydrogen]] gas, leading to bulging or deformation of the capacitor's case, and eventual venting of the electrolyte. In rare cases faulty capacitors have been reported to fail catastrophically.

High [[failure rate]]s occurred in many well-known brands of electronics, and were particularly evident in [[motherboard]]s, [[video card]]s, and [[power supply unit (computer)|power supplies]] of [[personal computer]]s.

[[Image:CapacitorExplosion.jpg|thumbnail|right|Exploded capacitor on a motherboard]]

A 2003 article in ''[[The Independent]]'' claimed that the cause of the faulty capacitors was due to a mis-copied formula. In 2001, a scientist working in the [[Rubycon Corporation]] in Japan stole a mis-copied formula for capacitors' electrolytes. He then took the faulty formula to the Luminous Town Electric company in China, where he had previously been employed. In the same year, the scientist's staff left China, stealing again the mis-copied formula and moving to Taiwan, where they created their own company, producing capacitors and propagating even more of this faulty formula of capacitor electrolytes.<ref name=IndArthur20030531>{{cite news |last1=Arthur |first1=Charles |title=Stolen formula for capacitors causing computers to burn out |url=https://www.independent.co.uk/news/business/news/stolen-formula-for-capacitors-causing-computers-to-burn-out-106907.html |date=31 May 2003 |archive-url=https://web.archive.org/web/20150525153000/http://www.independent.co.uk/news/business/news/stolen-formula-for-capacitors-causing-computers-to-burn-out-106907.html |archive-date=25 May 2015 |url-status=live |newspaper=The Independent |department=Business News |access-date=16 January 2020}}</ref>

== Incidence ==

Failing capacitors are mostly associated with some [[Pentium III]] motherboards; however some older [[Socket 7]] motherboards and newer [[Pentium 4]] and [[Athlon]] boards also suffer from them. Surprising most people in the computing industry, the first release of the [[iMac G5]] appears to suffer from them as well. (see [http://discussions.info.apple.com/webx?14@165.b3HZaJF4RMy.14@.68a31fdd this forum thread] and [http://www.pbase.com/flgator/imac_woes these photos]). The problem has apparently been rectified on the updated model of the iMac released in [[May 2005]]. Apple have also introduced an extended free repair program for early iMac G5's suffering from the problem - http://www.apple.com/support/imac/repairextensionprogram/ .

==History==

[[Image:PSU Caps.jpg|left|thumb|250px|A [[power supply unit]] with failed capacitors.]]

An increasing number are also being found in power supplies, monitors, video cards, and other devices.

===First announcements===

The fact that these failure-prone capacitors are still being used has angered many people, especially in cases where a motherboard populated mainly with high quality capacitors has one or two of the bad capacitors on it, leading to accusations of [[planned obsolescence]] on the part of motherboard manufacturers. Indeed, a strong case can be made that these capacitors (which often fail in 6 months or less) are still being manufactured, and are still being chosen over superior components by manufacturers to use in their products.

The first flawed capacitors linked to [[Taiwan]]ese raw material problems were reported by the specialist magazine ''Passive Component Industry'' in September 2002.<ref name= Paumanok/> Shortly thereafter, two mainstream electronics journals reported the discovery of widespread prematurely failing capacitors, from Taiwanese manufacturers, in motherboards.<ref name= "EDN">{{cite journal |last1= Sperling |first1= Ed |last2= Soderstrom |first2= Thomas |last3= Holzman |first3= Carey |title= Got Juice? |journal= [[EE Times]] |date= October 2002 |url= http://www.edn.com/electronics-news/4347300/Got-Juice- |access-date= 11 February 2014 |archive-date= 28 February 2014 |archive-url= https://web.archive.org/web/20140228054158/http://www.edn.com/electronics-news/4347300/Got-Juice- |url-status= live }}</ref><ref name= "Feb2003Spectrum"/>

These publications informed engineers and other technically interested specialists, but the issue did not receive widespread public exposure until Carey Holzman published his experiences about "leaking capacitors" in the [[overclocking]] performance community.<ref>Carey Holzman, Overclockers, Capacitors: Not Just For Abit Owners, Motherboards with leaking capacitors, 10/9, 2002, [http://www.overclockers.com/capacitors-not-just-for-abit-owners/] {{Webarchive|url=https://web.archive.org/web/20141018033035/http://www.overclockers.com/capacitors-not-just-for-abit-owners|date=18 October 2014}}</ref>

While this article deals primarily with desktop computer hardware, this problem is by no means limited to that area. These capacitors can also be found in some cameras, network switches, audio equipment, [[Digital Versatile Disc|DVD]] players, and a range of other devices. Even some car [[electronic control unit]]s have been found to have these same brands of often-failing capacitors. However, computer components are by far the most common ___location of these capacitors.

===Public attention===

As of May 2005, [http://www.ait.iastate.edu/sales/showitem.php?id=41 some evidence] shows that the failing [[Nichicon]] capacitors on the iMac, Intel, and Dell boards are due to a different problem (specifically, overfilling the capacitors with electrolyte) than the one discussed on this page (faulty electrolyte formula). However, the symptoms (both the effects on the system and the physical appearance of the capacitors) are the same as the other failing capacitors, as is how to identify them, and the required repair.

[[File:Brand auf Platine.jpg|thumb|right|Results of fire on a printed circuit board, caused by leaked electrolyte which [[short-circuit]]ed conductors carrying power]]

The news from the Holzman publication spread quickly on the Internet and in newspapers, partly due to the spectacular images of the failures – bulging or burst capacitors, expelled sealing rubber and leaking electrolyte on countless circuit boards. Many PC users were affected, and caused an avalanche of reports and comments on thousands of blogs and other web communities.<ref name= "Feb2003Spectrum">{{cite journal |last1= Chiu |first1= Yu-Tzu |first2= Samuel K |last2= Moore |title= Faults & Failures: Leaking capacitors muck up motherboards |journal= [[IEEE Spectrum]] |volume= 40 |issue= 2 |date= February 2003 |pages= 16–17 |issn= 0018-9235 |doi= 10.1109/MSPEC.2003.1176509 |url= https://spectrum.ieee.org/leaking-capacitors-muck-up-motherboards |access-date= 2014-08-22 |archive-date= 5 January 2018 |archive-url= https://web.archive.org/web/20180105214833/https://spectrum.ieee.org/computing/hardware/leaking-capacitors-muck-up-motherboards |url-status= live |url-access= subscription }}</ref><ref>{{cite web |first1=Paul |last1=Hales |title=Taiwanese component problems may cause mass recalls |url=http://www.theinquirer.net/inquirer/news/1026911/taiwanese-component-cause-mass-recalls |date=5 November 2002 |archive-url=https://web.archive.org/web/20110510135540/http://www.theinquirer.net/inquirer/news/1026911/taiwanese-component-cause-mass-recalls |archive-date=10 May 2011 |url-status=dead |publisher=[[The Inquirer]] |access-date=20 March 2023}}</ref><ref>{{Cite web |url=http://www.geek.com/science/capacitor-failures-plague-motherboard-vendors-551780/ |title=Capacitor failures plague motherboard vendors, GEEK, 7 February 2003 |access-date=14 December 2014 |archive-date=13 January 2015 |archive-url=https://web.archive.org/web/20150113173058/http://www.geek.com/science/capacitor-failures-plague-motherboard-vendors-551780/ |url-status=dead }}</ref>

== Identifying "capacitor plague" == [[Image:Buldging_tayeh_caps_2.jpg|thumbnail|right|Bulging or domed tops, no matter how slight, are a sure sign the capacitor has failed or is failing.]] [[Image:Badcaps-tayeh-4.jpg|thumbnail|right|Failed Tayeh capacitors which have vented through their aluminum tops.]] [[Image:Badcaps-choyo.jpg|thumbnail|right|Failed Choyo caps which have leaked onto the motherboard.]]

The most common way of identifying capacitors failing due to this cause is physical deformations:

*Bulging of the vent on the top of the capacitor

*Sitting crooked on the motherboard as the bottom rubber plug is pushed out

*Electrolyte (visible as brown gunk) leaked onto the motherboard from the base of the capacitor

*Venting from the top of the capacitor, visible as brown deposits, or a visible hole in the vent

The quick spread of the news also resulted in many misinformed users and blogs posting pictures of capacitors that had failed due to reasons other than faulty electrolyte.<ref>W. BONOMO, G. HOOPER, D. RICHARDSON, D. ROBERTS, and TH. VAN DE STEEG, Vishay Intertechnology, Failure modes in capacitors, [http://www.electronicproducts.com/Passive_Components/Capacitors/Failure_modes_in_capacitors.aspx] {{Webarchive|url=https://web.archive.org/web/20141214165112/http://www.electronicproducts.com/Passive_Components/Capacitors/Failure_modes_in_capacitors.aspx|date=14 December 2014}}</ref>

As the capacitor ages, its [[capacitance]] decreases while its [[Electrical resistance|equivalent series resistance]] (ESR) increases. When this happens, the capacitors no longer adequately serve their purpose of filtering the [[voltage]]s on the motherboard, and system instability results. Some common symptoms are:

*Not turning on all the time; having to hit reset or try turning the computer on again

*Instabilities (hangs, [[Blue Screen of Death|BSODs]], [[kernel panic]]s, etc), especially ones which get progressively worse with time

*Vcore or other system voltages fluctuating or going out of range, possibly with an increase in CPU temperature as the core voltage rises

*Memory errors, especially ones that get more frequent with time

*Spontaneously rebooting

*In case of onboard video cards, unstable image in some videomodes

*Failing to complete the [[Power-On Self Test|POST]], or rebooting before it is completed

*Never starting the POST; fans spin but the system appears dead

===Prevalence===

Unlike the physical signs, which are conclusive evidence the capacitors are failing, many of the operational signs may be caused by other factors, such as a failing [[power supply]], dust clogging a fan, bad [[Random Access Memory|RAM]], or other hardware problems. Instability once the operating system has loaded may indicate a software problem (such as some types of [[malware]], poorly-written [[device drivers]] or software), and not a hardware problem at all. If any of these symptoms are experienced, removing the system's case, and inspecting the capacitors, especially those around the [[Central processing unit|CPU]], may immediately identify capacitors as the cause. If there are no physical signs, an [[oscilloscope]] may be used to examine the voltage on the capacitors, with excessive [[ripple|ripple voltage]] being a sign the capacitors are not doing their job.

Most of the affected capacitors were produced from 1999 to 2003 and failed between 2002 and 2005. Problems with capacitors produced with an incorrectly formulated electrolyte have affected equipment manufactured up to at least 2007.<ref name=PCTools/>

Major vendors of motherboards such as [[Universal Abit|Abit]],<ref>{{Citation |newspaper= Heise |edition= online |title= Mainboardhersteller steht für Elko-Ausfall gerade |language= German |url= http://www.heise.de/newsticker/meldung/Mainboardhersteller-steht-fuer-Elko-Ausfall-gerade-Update-153175.html |place= [[Germany|DE]] |access-date= 14 December 2014 |archive-date= 25 December 2014 |archive-url= https://web.archive.org/web/20141225181326/http://www.heise.de/newsticker/meldung/Mainboardhersteller-steht-fuer-Elko-Ausfall-gerade-Update-153175.html |url-status= live }}.</ref> [[IBM]],<ref name= Paumanok/> [[Dell]],<ref>Michael Singer, CNET News, Bulging capacitors haunt Dell, 31 October 2005 [http://news.cnet.com/Bulging-capacitors-haunt-Dell/2100-1003_3-5924742.html] {{Webarchive|url=https://web.archive.org/web/20141214170952/http://news.cnet.com/Bulging-capacitors-haunt-Dell/2100-1003_3-5924742.html|date=14 December 2014}}</ref> [[Apple Inc.|Apple]], [[Hewlett-Packard|HP]], and [[Intel]]<ref>{{Cite web |url=http://news.cnet.com/PCs-plagued-by-bad-capacitors/2100-1041_3-5942647.html |title=Michael Singer, CNET News, PCs plagued by bad capacitors |access-date=14 December 2014 |archive-date=14 December 2014 |archive-url=https://web.archive.org/web/20141214170723/http://news.cnet.com/PCs-plagued-by-bad-capacitors/2100-1041_3-5942647.html |url-status=live }}</ref> were affected by capacitors with faulty electrolytes.

== Cause of the failing capacitors ==

The primary cause of these problems is [[industrial espionage]] gone wrong, with some [[Taiwan|Taiwanese]] electrolyte manufacturers using a stolen formula that was incomplete, and lacked ingredients needed to produce a stable capacitor. [[Institute of Electrical and Electronics Engineers|IEEE]]'s Spectrum has an overview of the situation, aptly titled "Leaking Capacitors Muck up Motherboards", after the tendency of the capacitors to leak gunk (electrolyte) onto the motherboard.

In 2005, Dell spent some US$420 million replacing motherboards outright and on the logistics of determining whether a system was in need of replacement.<ref>The guardian technology blog, How a stolen capacitor formula ended up costing Dell $300m [https://www.theguardian.com/technology/blog/2010/jun/29/dell-problems-capacitors] {{Webarchive|url=https://web.archive.org/web/20160303234931/http://www.theguardian.com/technology/blog/2010/jun/29/dell-problems-capacitors|date=3 March 2016}}</ref><ref name=NYT2010>{{cite news|last=Vance|first=Ashlee|author-link=Ashlee Vance|title=Suit Over Faulty Computers Highlights Dell's Decline|url=https://www.nytimes.com/2010/06/29/technology/29dell.html|accessdate=2012-03-08|newspaper=The New York Times|date=28 June 2010|archive-date=28 January 2021|archive-url=https://web.archive.org/web/20210128205229/https://www.nytimes.com/2010/06/29/technology/29dell.html|url-status=live}}</ref>

However, once the problems with these capacitors became known, there is evidence that motherboard manufacturers continued to use the bad capacitors, despite knowing they would certainly fail in a short time span. Only [[ABIT]] has admitted to the problems, while other manufacturers have given responses ranging from pretending nothing happened to strongly denying it and issuing legal threats to web sites mentioning their names in conjunction with capacitor failures.

Many other equipment manufacturers unknowingly assembled and sold boards with faulty capacitors, and as a result the effect of the capacitor plague could be seen in all kinds of devices worldwide.

When the capacitor is charged, the [[water]]-based electrolyte becomes unstable, and breaks down producing [[hydrogen]] gas. Since an electrolytic capacitor of the kind found on motherboards is sealed, the pressure builds up within the capacitor. As the pressure grows, the flat metal tops of the capacitors begin to bend, or the rubber sealing plug is pushed down. Eventually the pressure exceeds the strength of the case, and venting occurs, either by blowing out the rubber bottom of the capacitor, or bursting the scored metal vent on the top of the capacitor. Depending on exactly when this happens, effects can range from a pop and a hissing noise to a small explosion. Venting is typically messy, and the electrolyte must be cleaned off the motherboard to prevent further damage.

Because not all manufacturers had offered recalls or repairs, [[do it yourself]] repair instructions were written and published on the Internet.<ref>{{Citation |title= Repair and bad capacitor information |url= https://www.capacitorlab.com/ |publisher= Capacitor Lab |access-date= 26 April 2022 |archive-date= 12 April 2022 |archive-url= https://web.archive.org/web/20220412005757/http://www.capacitorlab.com/ |url-status= live }}.</ref>

== Replacement of failing capacitors == [[Image:Recapped_964d_pro_01.jpg|thumbnail|right|An MSI 694D Pro [[motherboard]] with all new Nichicon capacitors. The new high-quality replacements were physically larger than the old capacitors, leading to some being installed on their sides to make sure they don't interfere with expansion cards.]]

A few repair shops specialize in replacement of motherboard capacitors, however most will simply diagnose the system as needing a new motherboard. Also, in many cases, the cost of having a technician repair the board exceeds the cost of a new replacement board. Due to these factors, many people choose to replace the capacitors themselves.

===Responsibility===

Soldering on motherboards (which are typically six or more layers and may have [[ground plane]]s) can be challenging, and without the right equipment or skill, can easily render a repairable board into an unrepairable one. Before replacing the capacitors on a motherboard (typically referred to as "recapping"), research has to be done into the proper low-[[Equivalent series resistance|ESR]] replacements and best soldering methods for the board in question.

In the November/December 2002 issue of ''Passive Component Industry'', following its initial story about defective electrolyte, reported that some large Taiwanese manufacturers of electrolytic capacitors were denying responsibility for defective products.<ref name=Liotta>{{cite journal|first1=Bettyann |last1=Liotta |title=Taiwanese Cap Makers Deny Responsibility |journal=Passive Component Industry |date=November 2002 |volume=4 |number=6 |pages=6, 8–10 |url=http://old.passivecomponentmagazine.com/files/archives/2002/PCI_02_06Nov-Dec.pdf |accessdate=2015-11-03 |publisher=Paumanok Publications |url-status=dead |archiveurl=https://web.archive.org/web/20151120065846/http://old.passivecomponentmagazine.com/files/archives/2002/PCI_02_06Nov-Dec.pdf |archivedate=20 November 2015}}</ref>

While industrial customers confirmed the failures, they were not able to trace the source of the faulty components. The defective capacitors were marked with previously unknown brands such as "Tayeh", "Choyo", or "Chhsi".<ref>{{cite web |url=http://www.opencircuits.com/Capacitor_plague |title=Capacitor plague, identifizierte Hersteller (~identified vendors) |publisher=Opencircuits.com |date=2012-01-10 |accessdate=2014-09-03 |archive-date=11 March 2015 |archive-url=https://web.archive.org/web/20150311101131/http://www.opencircuits.com/Capacitor_plague |url-status=dead }}</ref> The marks were not easily linked to familiar companies or product brands.

== Brands and specs ==

The motherboard manufacturer ABIT Computer Corp. was the only affected manufacturer that publicly admitted to defective capacitors obtained from Taiwan capacitor makers being used in its products.<ref name=Liotta/> However, the company would not reveal the name of the capacitor maker that supplied the faulty products.

=== Bad ===

==Symptoms==

*Canicon

*Chhsi

*Choyo

*CTC

*Fuhjyyu (found in [[Antec]] and FSP (and so many others licensed from FSP, for example [[Zalman]]), Tagan and so many other power supplies to this day)

*Gloria

*GSC

*(G) Luxon (also G-Luxon) (Found in some older [[Elitegroup Computer Systems|ECS]] motherboards)

*Hermei

*I.Q.

*JDEC

*JPCON

*Jun Fu (found in some Deer power supplies)

*OST (found on some PCCHIPS, [[Elitegroup Computer Systems|ECS]], [[ASUS]], and [[Epox|EPoX]] motherboards to this day)

*Raycon

*Lelon

*Licon

*Taicon (found on [[Asrock|ASRock]] motherboards and BFG video cards, part owned by [[Nichicon]] or so their website claims)

*PCE-TUR (found in Enermax power supplies and in Seasonic power supplies (300W, prod. 2002))

*FUH YIN

====Common Suspicious brands =characteristics===

The non-solid aluminium electrolytic capacitors with improperly formulated electrolyte mostly belonged to the so-called "low [[equivalent series resistance]] (ESR)", "low [[Electrical impedance|impedance]]", or "high ripple current" e-cap series. The advantage of e-caps using an electrolyte composed of 70% water or more is, in particular, a low ESR, which allows a higher [[Ripple (electrical)|ripple current]], and decreased production costs, water being the least costly material in a capacitor.<ref name=Uzawa>{{cite journal |last1=Uzawa |first1=Shigeru |last2=Komatsu |first2=Akihiko |last3=Ogawara |first3=Tetsushi |last4=Rubycon Corporation |title=Ultra Low Impedance Aluminium Electrolytic Capacitor with Water based Electrolyte |journal=Journal of Reliability Engineering Association of Japan |date=2002 |volume=24 |number=4 |pages=276–283 |id=Accession number 02A0509168 |issn=0919-2697}}</ref>

*Tayeh — This brand appears to not actually exist, indicating the actual manufacturers were wary of putting their name on their product; and probably a fake of "Ta-Keh", a genuine maker of high-end capacitors for [[audio]] equipment, used by [[Denon]] and [[Technics]] ([[Panasonic]]).

*[[Rulycon]] — A clone of "[[Rubycon (company)|Rubycon]]", a well-known manufacturer of high-quality capacitors, right down to the exact style of the cases and the fonts used for lettering

{| class="wikitable centered"

==== Admitted ====

|+ Comparison of aluminium e-caps with different non-solid electrolytes

!Electrolyte

!Manufacturer<br/>series, type

!Dimensions<br>D × L<br>(mm)

!Max. ESR<br/>at 100&nbsp;kHz, 20&nbsp;°C<br/>(mΩ)

!Max. ripple current<br>at 85/105&nbsp;°C<br/>(mA)

|-

| Non-solid<br>organic electrolyte || Vishay<br>036 RSP, 100&nbsp;μF, 10&nbsp;V || 5 × 11 || 1000 || 160

|-

| Non-solid, ethylene-glycol,<br>boric-acid (borax) electrolyte || NCC<br> SMQ, 100&nbsp;μF, 10&nbsp;V || 5 × 11 || 900 || 180

|-

| Non-solid<br>water-based electrolyte || Rubycon<br>ZL, 100&nbsp;μF, 10&nbsp;V || 5 × 11 || 300 || 250

|-

|}

===Premature failure===

*Jackcon — The only capacitor manufacturer to own up to their mistake; they are also the only one to issue free replacement capacitors to people who had theirs fail. Their new products appear to be of greater quality.

All electrolytic capacitors with non-solid electrolyte age over time, due to evaporation of the electrolyte. The [[capacitance]] usually decreases and the ESR usually increases. The normal lifespan of a non-solid electrolytic capacitor of consumer quality, typically rated at 2000&nbsp;h/85&nbsp;°C and [[operating temperature|operating]] at 40&nbsp;°C, is roughly 6 years. It can be more than 10 years for a 1000&nbsp;h/105&nbsp;°C capacitor operating at 40&nbsp;°C. Electrolytic capacitors that operate at a lower temperature can have a considerably longer lifespan.

The capacitance should normally degrade to as low as 70% of the rated value, and the ESR increase to twice the rated value, over the normal life span of the component, before it should be considered as a "degradation failure".<ref name=Albertsen>{{cite web |url=http://jianghai-europe.com/wp-content/uploads/JIANGHAI_Elcap_Lifetime_-_Estimation_AAL.pdf |title=A. Albertsen, Electrolytic Capacitor Lifetime Estimation |accessdate=2014-09-04 |archive-date=17 January 2015 |archive-url=https://web.archive.org/web/20150117042507/http://jianghai-europe.com/wp-content/uploads/JIANGHAI_Elcap_Lifetime_-_Estimation_AAL.pdf |url-status=live }}</ref><ref name="Parler">Sam G. Parler, Cornell Dubilier, Deriving Life Multipliers for Electrolytic Capacitors [http://www.newark.com/pdfs/techarticles/cornell/multipliers.pdf] {{Webarchive|url=https://web.archive.org/web/20160304042611/http://www.newark.com/pdfs/techarticles/cornell/multipliers.pdf|date=4 March 2016}}</ref> The life of an electrolytic capacitor with defective electrolyte can be as little as two years. The capacitor may fail prematurely after reaching approximately 30% to 50% of its expected lifetime.

==== Possibly reformed ====

===Electrical symptoms===

*Teapo — Teapo has denied these claims, but evidence suggests their new capacitors are sound. However their older ones appear to suffer from the same problems other brands do.

The electrical characteristics of a failed electrolytic capacitor with an open vent are the following:

*NRSY — with X-shaped vents are suspect; the new NRSY capacitors with K vents and are genuinely high-quality.

*capacitance value decreases to below the rated value

*ESR increases to very high values.

Electrolytic capacitors with an open vent are in the process of drying out, regardless of whether they have good or bad electrolyte. They always show low capacitance values and very high ohmic ESR values. Dry e-caps are therefore electrically useless.

=== Good ===

E-caps can fail without any visible symptoms. Since the electrical characteristics of electrolytic capacitors are the reason for their use, these parameters must be tested with instruments to definitively decide if the devices have failed. But even if the electrical parameters are out of their specifications, the assignment of failure to the electrolyte problem is not a certainty.

*[[Rubycon (company)|Rubycon]]

*[[Nichicon]]

*Panasonic

*Sanyo

*[[Nippon Chemi-con]]

*United Chemi-Con

Non-solid aluminium electrolytic capacitors without visible symptoms, which have improperly formulated electrolyte, typically show two electrical symptoms:

== Specifications of capacitors used on motherboards ==

*relatively high and fluctuating [[Leakage (electronics)|leakage current]]<ref>The Aluminium Electrolytic Condenser, H. 0. Siegmund, Bell System Technical Journal, v8, 1. January 1229, pp.&nbsp;41–63</ref><ref>A. Güntherschulze, H. Betz, Elektrolytkondensatoren, Verlag Herbert Cram, Berlin, 2. Auflage 1952</ref>

*increased capacitance value, up to twice the rated value, which fluctuates after heating and cooling of the capacitor body

===Visible symptoms===

Typically, only the capacitors with capacitances over 480 [[Microfarad|µF]] fail, since the lower capacitance ones are usually made with a different electrolyte. When motherboards are recapped, only the ones over 480 [[Microfarad|µF]] are replaced for this reason. However, some smaller values have been known to fail, so sometimes replacing every vented electrolytic is necessary to permanently repair a motherboard. Any motherboard with these brands of capacitors is very likely to fail prematurely, and due to the possibility of bad capacitors damaging other components, a preemptive replacement of the capacitors is sometimes advisable.

[[File:Blown up electrolytic capacitor.jpg|thumb|Closeup of a broken electrolytic capacitor vent and dried electrolyte residue]]

When examining a failed electronic device, the failed capacitors can easily be recognized by clearly visible symptoms that include the following:<ref name="SilChip2003"/>

== What happens after capacitors fail ==

While failing capacitors typically results in the aforementioned system instabilities, occasionally failed capacitors, especially on certain motherboards, will lead to a failure of the [[voltage regulator]]s on the motherboard. There are two common theories on why this happens:

*Bulging of the vent on top of the capacitor. (The "vent" is stamped into the top of the casing of a can-shaped capacitor, forming a seam that is meant to split to relieve pressure build-up inside, preventing an explosion.)

The first (and simpler) theory is that the failing capacitors can fail such as to form a [[short circuit]], or with a very high [[leakage]] current, overloading the voltage regulators and causing them to overheat.

*Ruptured or cracked vent, often accompanied by visible crusty rust-like brown or red dried electrolyte deposits.

*Capacitor casing sitting crooked on the circuit board, caused by the bottom rubber plug being pushed out, sometimes with electrolyte having leaked onto the motherboard from the base of the capacitor, visible as dark-brown or black surface deposits on the PCB.<ref>Blown, Burst and Leaking Motherboard Capacitors - A Serious Problem, PCSTATS, 15 January 2005 [http://www.pcstats.com/articleview.cfm?articleID=195] {{Webarchive|url=https://web.archive.org/web/20160816143329/http://www.pcstats.com/articleview.cfm?articleID=195|date=16 August 2016}}</ref> The leaked electrolyte can be confused with thick elastic glue sometimes used to secure the capacitors against shock. A dark brown or black crust up the side of a capacitor is invariably glue, not electrolyte. The glue itself is harmless.

{{gallery |title=Visible symptoms of failed electrolytic capacitors |align=center|File:Bad Capacitor 01.jpg|Failed Chhsi capacitor with crusty electrolyte buildup on the top

The second theory is that as the capacitance decreases and the ESR increases, the buck controller for the voltage regulator increases the switching frequency to compensate. Since most of the [[MOSFET]]'s heat output is produced during the switching transitions, this causes them to overheat.

|File:Defekte Kondensatoren.jpg|Failed capacitors next to CPU motherboard socket

|File:Badcaps-tayeh-4.jpg|Failed Tayeh capacitors which have vented subtly through their aluminium tops

|File:Elko-mit-ausgedrücktem-Gummistopfen.jpg|Failed electrolytic capacitors with swollen can tops and expelled rubber seals, dates of manufacture "0106" and "0206" (January and February 2006)

|File:vp6 blown capacitor.jpg|Failed capacitor has exploded and exposed internal elements, and another has partially blown off its casing

|File:Badcaps-choyo.jpg|Failed Choyo capacitors (black color) which have leaked brownish electrolyte onto the motherboard

}}

==Investigation==

The most common failure mode of the voltage regulator is for the [[MOSFET]] to short circuit, causing the system's power supply (5 or 12 [[volt]]s depending on the motherboard) to be applied directly to the CPU, [[Northbridge (computing)|northbridge]], RAM, or other components, causing widespread damage and destruction. As such, a motherboard with symptoms of failing capacitors should be taken out of service until it is repaired, to prevent further damage.

===Implications of industrial espionage===

[[Industrial espionage]] was implicated in the capacitor plague, in connection with the theft of an electrolyte formula. A materials scientist working for [[Rubycon Corporation|Rubycon]] in [[Japan]] left the company, taking the secret water-based electrolyte formula for Rubycon's ZA and ZL series capacitors, and began working for a Chinese company. The scientist then developed a copy of this electrolyte. Then, some staff members who defected from the Chinese company copied an incomplete version of the formula and began to market it to many of the [[aluminium]] electrolytic manufacturers in Taiwan, undercutting the prices of the Japanese manufacturers.<ref name="Paumanok" /><ref>{{Citation|title=Low-ESR Aluminium Electrolytic Failures Linked to Taiwanese Raw Material Problems |url=http://www.molalla.net/members/leeper/alumin~1.pdf |publisher=Molalla |url-status=dead |archiveurl=https://web.archive.org/web/20120426000850/http://www.molalla.net/members/leeper/alumin~1.pdf |archivedate=26 April 2012}}</ref> This incomplete electrolyte lacked important proprietary ingredients which were essential to the long-term stability of the capacitors<ref name="Feb2003Spectrum" /><ref name="SilChip2003">{{cite web |url=http://www.siliconchip.com.au/cms/A_30328/article.html |work=Silicon Chip |title=Motherboard Capacitor Problem Blows Up |place=[[Australia|AU]] |date=2003-05-11 |accessdate=2012-03-07 |archive-date=14 June 2012 |archive-url=https://web.archive.org/web/20120614224125/http://www.siliconchip.com.au/cms/A_30328/article.html |url-status=live }}</ref> and was unstable when packaged in a finished aluminium capacitor. This faulty electrolyte allowed the unimpeded formation of hydroxide and produced hydrogen gas.<ref name="HHpaper">{{Citation |last1= Hillman |first1= Craig |last2= Helmold |first2= Norman |year= 2004 |title= Identification of Missing or Insufficient Electrolyte Constituents in Failed Aluminium Electrolytic Capacitors |url= http://www.dfrsolutions.com/pdfs/2004_Electrolyte_Hillman-Helmold.pdf |publisher= DFR solutions |access-date= 2 January 2009 |archive-date= 26 June 2011 |archive-url= https://web.archive.org/web/20110626204424/http://www.dfrsolutions.com/pdfs/2004_Electrolyte_Hillman-Helmold.pdf |url-status= live }}</ref><ref>{{cite web |title=Low-ESR Aluminum Electrolytic Failures Linked to Taiwanese Raw Material Problems |url=https://www.burtonsys.com/bad_BP6/story3.html |access-date=16 March 2022 |archive-date=22 June 2017 |archive-url=https://web.archive.org/web/20170622062611/http://www.burtonsys.com/bad_BP6/story3.html |url-status=live }}</ref>

There are no public court proceedings related to the alleged theft, as Rubycon's complete electrolyte formula remained secure. However, independent laboratory analysis of defective capacitors has shown that many of the premature failures appear to be associated with high water content and missing inhibitors in the electrolyte, as described below.<ref name="HHpaper"/>

== External links ==

*[http://www.badcaps.net/ BadCaps] — A repair site offering tutorials on proper soldering and replacement capacitor selection

*[http://www.siliconchip.com.au/cms/A_30328/article.html Motherboard Capacitor Problem Blows Up] — An article about capacitor failures

===Incomplete electrolyte formula===

Unimpeded formation of hydroxide (hydration) and associated hydrogen gas production, occurring during "capacitor plague" or "bad capacitors" incidents involving the failure of large numbers of aluminium electrolytic capacitors, has been demonstrated by two researchers at the [[Center for Advanced Life Cycle Engineering]] of the [[University of Maryland, College Park|University of Maryland]] who analyzed the failed capacitors.<ref name="HHpaper"/>

The two scientists initially determined, by [[ion chromatography]] and [[mass spectrometry]], that there was hydrogen gas present in failed capacitors, leading to bulging of the capacitor's case or bursting of the vent. Thus it was proved that the oxidation takes place in accordance with the first step of aluminium oxide formation.

Because it has been customary in electrolytic capacitors to bind the excess hydrogen by using reducing or [[depolarizer|depolarizing]] compounds, such as [[aromaticity|aromatic]] nitrogen compounds or [[amine]]s, to relieve the resulting pressure, the researchers then searched for compounds of this type. Although the analysis methods were very sensitive in detecting such pressure-relieving compounds, no traces of such agents were found within the failed capacitors.

In 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, the [[pH]] value of the electrolyte could be measured. The electrolyte of the faulty Taiwanese capacitors was alkaline, with a pH of between 7 and 8. Good comparable Japanese capacitors had an electrolyte that was acidic, with a pH of around 4. As it is known that aluminium can be dissolved by alkaline liquids, but not that which is mildly acidic, an [[energy-dispersive X-ray spectroscopy]] (EDX or EDS) fingerprint analysis of the electrolyte of the faulty capacitors was made, which detected dissolved aluminium in the electrolyte.

To protect the metallic aluminium against the aggressiveness of the water, some phosphate compounds, known as inhibitors or [[Passivation (chemistry)|passivators]], can be used to produce long-term stable capacitors with high-aqueous electrolytes. Phosphate compounds are mentioned in patents regarding electrolytic capacitors with aqueous electrolytic systems.<ref>Chang, Jeng-Kuei, Liao, Chi-Min, Chen, Chih-Hsiung, Tsai, Wen-Ta, Effect of electrolyte composition on hydration resistance of anodized aluminium oxide [http://www.sciencedirect.com/science/article/pii/S0378775304006743] {{Webarchive|url=https://web.archive.org/web/20150924173258/http://www.sciencedirect.com/science/article/pii/S0378775304006743|date=24 September 2015}}</ref> Since phosphate ions were missing and the electrolyte was also alkaline in the investigated Taiwanese electrolytes, the capacitor evidently lacked any protection against water damage, and the formation of more-stable alumina oxides was inhibited. Therefore, only aluminium hydroxide was generated.

The results of chemical analysis were confirmed by measuring electrical capacitance and leakage current in a long-term test lasting 56&nbsp;days. Due to the chemical corrosion, the oxide layer of these capacitors had been weakened, so after a short time the capacitance and the leakage current increased briefly, before dropping abruptly when gas pressure opened the vent. The report of Hillman and Helmold proved that the cause of the failed capacitors was a faulty electrolyte mixture used by the Taiwanese manufacturers, which lacked the necessary chemical ingredients to ensure the correct pH of the electrolyte over time, for long-term stability of the electrolytic capacitors. Their further conclusion, that the electrolyte with its alkaline pH value had the fatal flaw of a continual buildup of hydroxide without its being converted into the stable oxide, was verified on the surface of the anode foil both photographically and with an EDX-fingerprint analysis of the chemical components.

==See also==

* [[RKM code]]

==References==

{{Reflist|30em}}

==Further reading==

*H. Kaesche, Die Korrosion der Metalle - Physikalisch-chemische Prinzipien und aktuelle Probleme, Springer-Verlag, Berlin, 2011, {{ISBN|978-3-642-18427-7}}

*C. Vargel, Corrosion of Aluminium, 1st Edition, 2 October 2004, Elsevier Science, Print Book {{ISBN|978-0-08-044495-6}}, eBook {{ISBN|978-0-08-047236-2}}

*W. J. Bernard, J. J. Randall Jr., The Reaction between Anodic Aluminium Oxide and Water, 1961 ECS - The Electrochemical Society [http://jes.ecsdl.org/content/108/9/822]

*Ch. Vargel, M. Jacques, M. P. Schmidt, Corrosion of Aluminium, 2004 Elsevier B.V., {{ISBN|978-0-08-044495-6}}

*Patnaik, P. (2002). Handbook of Inorganic Chemicals. McGraw-Hill. {{ISBN|0-07-049439-8}}.

*Wiberg, E. and Holleman, A. F. (2001). Inorganic Chemistry. Elsevier. {{ISBN|0-12-352651-5}}

{{DEFAULTSORT:Capacitor Plague}}

[[Category:Capacitors]]

[[Category:Computer hardware]]

[[Category:Motherboard]]

[[Category:Corporate scandals]]

[[Category:Product safety scandals]]