Recently I have encountered some bad capacitors on a graphic card of my client.  The user was randomly facing black screen right after boot up until one day he could not solve the problem after many reboots.  Surprisingly the monitor can still show the BIOS detail but show nothing after the operating system has loaded (noticed from HDD LED).  It was tested not the problem of the monitor.

The first picture above shows 3 bad capacitors, and the second picture above shows a good capacitor.

While I was doing some research on why is this happening, I found the story behind.  It is called capacitor plague, an issue that discovered in 1999 but the poor quality capacitors were still being sold or integrated into designs as of early 2007.

[Capacitor plague is involved the common premature failure of certain brands of electrolytic capacitors used in various electronics equipment.  An incorrect electrolyte formula within a faulty capacitor causes the production of hydrogengas, leading to bulging or deformation of the capacitor’s case, and eventual venting of the electrolyte.] - taken from Wikipedia.

It is not easy to detect the capacitor plague because the device such as motherboard, DVD player, or even camera that have bad capacitor may still be working.  This is because the capacitors might still have 50% or lower of its capability to perform its job (but it gets worse as the time goes).  However, the system will definitely shows some funny things from time to time.

I am not sure about DVD player or camera, but for a computer system, if it is showing the following symptoms such as freeze intermittently, blue screen, memory error, fan turning when switched on but nothing happen, system reboot by itself etc., it might be the problem of the capacitor.

However, this type of capacitor (electrolytic capacitor) has a lifespan and its life get shorten as the heat increases. The capacitance may degrade to 4% of the original value (with the problem of capacitor plague), as opposed to an expected 50% capacity degradation over the lifetime.

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The things that surprised me the most is :-

[The root cause of the failing capacitors is industrial espionage gone wrong.   Several Taiwanese electrolyte manufacturers were using a stolen formula that was incomplete, and lacked ingredients needed to produce a stable capacitor.] - taken from Wikipedia.

Human use tools to solve problem, but also create problems while the tools are being developed. - (C) ColinJong 2010.

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The conclusion is that my client chose to use the on-board graphic temporarily and I guess it might be a short circuit instead of capacitor plague.