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There is a major issue concerning Low ESR Taiwanese aluminium electrolytic capacitors which are used in many devices to smooth the power supply to chips. The legend goes that a scientist working for Rubycon in Japan left the company and began working for a Chinese company where he developed a copy of the Rubycon P-50 water based electrolyte formula. His staff copied the formula and went to Taiwan where they began to product tons of this electrolyte and sold it to many Taiwanese capacitor manufacturers. |
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Unfortunately the formula was incomplete and did not contain the proper additives to stop the build up of hydrogen gas inside the capacitor cans which is caused by electrolysis occurring. The build up of gas caused the capacitors to fail way before their normal lifetime by bursting the vents at the top of the cans and leaking electrolyte.
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Motherboards with these bad capacitors installed would begin to have problems like general instability, difficulty to turn the computer on from cold and eventually when several capacitors vented they would shut down and remain dead until the capacitors were replaced. |
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Lelon brand bad caps on a MSI-6337 board. You can see that one cap is completely flat at the top whilst the others have abnormal swelling at the top and a small discharge of brown electrolyte in the middle. The board is completely unstable at this stage, crashing all the time. |
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The most unlucky people would find that some of the capacitors had shorted causing burn marks at the ram/cpu/pci/atx connector and damaging ram, cards processors. Not only motherboards are affected by this issue however, other devices like graphics cards, audiovisual equipment, monitors even TFTs contain these capacitors. There was even a similar issue with bad smt capacitors (which are very small). Failures in a certain range of Sony video cameras with these caps are well publicised and there is a class action against Sony in the USA for this.
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The problem with motherboards is that if the board is trashed after 2-3 years the user could find it difficult to find a replacement board because the platform is obsolete. So a new processor/ram/psu would be required to support the new board and that would be a large expense. |
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The question is whether the story of industrial espionage/stolen formula is actually true because this problem does not seem to be going away. We are still seeing boards only a year old with this problem. Perhaps the manufacturers like your product to fail out of warranty so you go and spend more money. |
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Gloria caps on a 3com officeconnect 8port hub. The two larger ones in the foreground have failed, they are swelling with a discharge of electrolyte in the centre. At this point the unit is making an air sound or hissing as the smt components complain about the bad power supplied by the failed caps. |
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What manufacturers of bad caps should we look out for? There are certain capacitor manufacturers which produce aluminium electrolytic radial capacitors which are seen in practice to fail in an unacceptably short period of time. These manufacturers are as follows : |
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| Chhsi |
| Choyo |
| CTC |
| Fuhjyyu |
| Gloria |
| G-Luxon |
| Gsc |
| Hermei |
| I.Q. |
| Jackcon |
| JDEC |
| Jee |
| Jpcon |
| Jun-Foo |
| Lelon |
| Licon |
| Nrsy |
| Ost |
| Raycon |
| Rulycon |
| Stone |
| Supacon |
| Su'scon |
| Tayeh |
| Teapo |
| Tocon |
| Wendell |
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It would not be fair to say that these companies will always produce bad caps but in practice we have seen actual evidence of their aluminium electrolytic radial Low ESR products failing and if you have these products on your motherboard and your computer is unstable then it would be best to remove it from service until you get the capacitors replaced. You can often read the manufacturers name on the side of the capacitors if you look carefully. |
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G-Luxon caps on a Gigabyte GA-7ZXE motherboard. You can see that two of the caps are swollen at the top and have an orange discharge of the electrolyte. This board is interesting because it has also many G-Luxon 330uf 25V caps. It is recommended to recap these with good 1000uf 16V caps even though 330uf is below the recommended 1000uf level to replace capacitors. This unit was displaying instability months before the caps finally vented. |
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What sizes of capacitors are affected? well if the capacitors have vents or markings like a cross carved into their tops then they are likely to be candidates. It is commonly accepted that capacitors 1000uf and above may fail. However we have seen even caps of lower values like 330uf 25V and also in rare cases problems with very small caps getting hot and causing problems. |
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What manufacturers are guaranteed to make good caps? it is guaranteed that Panasonic, Rubycon, Sanyo, Nichicon make good Low ESR caps. However even these can fail earlier than expected if you subject them to high heat, for instance if your case has bad cooling or your heatsinks and fans are clogged up with dust. A cap may even be right next to or touching your hot heatsink subjecting it to high temperatures. |
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Rubycon ZL Series, a popular range of good caps for motherboards. The K markings are distinctive and also used by Sanyo but in a different style. Watch out for Rulycon caps which are counterfeit Rubycons. |
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Rubycon YXG Series, another popular range of good caps for motherboards |
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What motherboard should I buy to avoid this problem? you could try an Intel original board, I have seen consistently good caps on these boards. Also you may have good luck with ABIT or ASUS but check before you buy. |
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Read on to the next section to find out how you can replace the bad capacitors yourself. |
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