Capacitor Plague

example 1

If you have never heard of capacitor plague, you’re not alone. I had no idea it existed until a year ago when I found a computer at work that simply would not turn on. Usually this means a bad PSU, but this was not the case. Upon opening up the computer, I found half a dozen capacitors that had vented and leaked out. Reading a bit further, I found out that it was not an isolated case but quite widespread.

According to The Guardian, this issue stems from corporate espionage in Asia where a scientist who worked for Rubycon left to work for another capacitor company in China bringing the capacitor electrolyte solution with him. Later that year, the scientist’s staff defected to Taiwan stealing the solution but missed a crucial ingredient that gave the electrolytic solution longevity, resulting in leaking of hydrogen gas and bursting of the metal body of the capacitor. Rather than lasting years, these capacitors would last months. This issue affected major companies like Dell, HP, IBM, Apple, among others and did not only affect personal computers but power supplies, flat panel displays, audio equipment, etc. It also appears that the problem became widespread in 2002 and was still being reported in 2013, however has receded since 2010.


What does this mean to everyone else? Having electronics die prematurely and not turn on again due to a small replaceable component. The only way to find out if you have bad caps is to actually open up your electronics and take a look. From what I found, running continuously in hotter temperatures (bad ventilation or a hot room) quickens capacitor plague symptoms. Unlikely the story above, many caps I replaced were Rubycon and presumably legitimate.

If your electronics has capacitor plague, what do you do? Replace them! And don’t wait until your computer fails to do so. A failing capacitor will have decreased capacitance and fail to filter out higher ripple voltages that can damage components of your motherboard such as the CPU. Typically you can tell when a computer BSOD’s often for no reason, restarts by itself, crashes often, basically doesn’t work the way it is supposed to.

What do you need?
1) a soldering tool, a good one maybe at 60W that gets you a high enough temperature for desoldering
2) a desoldering pump and/or wick
3) the replacement capacitor

For all the necessary information for the replacement capacitor, Badcaps and The Cap King are fantastic resources. Some older capacitors such as Rubycon MCZs are not even made anymore so asking for good alternatives is a good idea. Make sure your replacement cap is the same in terms of capacitance, voltage rating, temperature, ripple current/ESR, and size. In some cases you can get better stats, such as higher ripple current or voltage rating. If you are in Canada, Digi-Key is a great place to buy from.

First identify the problematic caps. Then desolder and/or remove them from the board. Although there are likely more refined methods by those electronic connoisseurs out there, my brute force method seems the easiest; heat up the contact solder and pull the component right off the board. Then I stick the desoldering tip into the top of the contact hole and with the desoldering pump, on the back side of the board, pull the solder out. Anything I cannot remove that way I use the wick, but typically it is pretty clean and workable at this point. Lastly, put the new cap leads into the holds and resolder the capacitor back on. Unfortunately the image above shows the removal of a bad cap and I put a new cap that is slightly smaller in diameter. I was not very mindful of the diameter when I purchased all the caps together, but it still works.

With this method, I repaired all five computers and a router and it only cost me 10$ to do so. Just make sure you do it properly, as you end up in the same place or worse if you don’t sodder properly or overheat the capacitor.

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