Electrolytic capacitors, the weak spot in modern consumer electronic products?

These days modern consumer electronics products tend to be pretty damn reliable, but an online video I watched recently reminded me that the one component that we often first suspect when a failure occurs is the good old aluminium electrolytic capacitor.

The video I was watching was on the blog of Australian electronic engineer Dave Jones. Dave was looking at a Chinese made Soniq L32V12A 32″ LCD TV and immediately suspected the problem lay in the electrolytic capacitors in the Megmeet branded power supply. In this case the capacitors were intact and tested ok but it was interesting that rather than being from a well known capacitor manufacturer he found an unknown brand that was only one letter different from major electronics brand “Samsung”, cheeky or what!

Modern mains electric powered electronics use switched mode power supplies and the circuits in these use some fairly hefty electrolytic capacitors which are made to work hard. Manufacturers looking to keep costs down have to balance component costs and circuit board layout against reliability. Even in products from major well thought of brands electrolytic capacitor failure can be a known issue, for budget brands producing as cheaply as possible the temptation to not use capacitors from reputable companies such as Rubycon and Sanyo is even greater.

Capacitor plague.

Back in the early 2000’s a number of electrolytic capacitor manufacturers bought in good faith a poorly formulated electrolyte to use in their capacitors. The resulting sub standard components were widely used in a variety of equipment which then suffered very premature failures due to capacitor faults caused by corrosion attributable to the liquid electrolyte. Such was the impact that there is even a Wikipedia page on the problem of the so called capacitor plague.

Some pretty major names in computer manufacture were caught up in this capacitor plague problem with electrolytic capacitors failing on motherboards. I have swapped out the motherboards back in the mid and late 2000’s on a large number of Dell GX270 and SX270 desktop computers with obviously bulging or burst electrolytic capacitors. Thankfully once the issue came to light future motherboards were assembled using better quality capacitors.

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