If your system is behaving erratically or strangely, it's worth doing a quick visual check to determine if failing capacitors might be the cause. The first time I encountered this I was frustrated by my inability to troubleshoot the strange behaviour of the system in question, till I removed the motherboard entirely and inspected it under a strong light. Noticing some slight bulging of the capacitors, I started searching on Google and found that many others were starting to have similar problems.
Since that time about a year ago, I have encountered many instances of this happening, in various brands. Click HERE to see some of the brands being found to have this problem; I also found bulging capacitors on a failed AGP graphics card recently. In every instance the user of the system was experiencing intermittent problems, which they were unable to diagnose.
Capacitors on motherboards are used to eliminate voltage ripples. If a line carrying DC voltage has ripples or spikes in it, a capacitor can smooth out the voltage by absorbing the excess from the peaks, and filling in the troughs.
The below pictures I've chosen show relatively advanced cases; basically, if you find ANY swelling of capacitors / capacitor tops, or ANY leaking, then you have a problem. It needn't be leaking out everywhere, just a trace / faint indication is enough to suggest this is where your trouble is coming from. Apart from eventual self-destruction, leakage from these capacitors may also damage nearby components and circuit board copper, as the electrolyte compounds are corrosive.
The picture shows some capacitors that have started to bulge.
This picture shows some capacitors that are leaking (they are the green components).
How Capacitors Work links you to the 'How Stuff Works' website to learn exactly what a capacitor is and how it's used in electronics.
Low-ESR Aluminum Electrolytic Failures Linked to Taiwanese Raw Material Problems From NIC Components (Nippon Industries) website, an excerpt here: "Unfortunately, the staff members who defected from Luminous Town Electric with the formula copied only the partial formula, and the subsequent electrolyte produced was unstable when packaged in a finished aluminum capacitor. The instability of the electrolyte in the low-ESR aluminum electrolytic capacitors using this water-based electrolyte leads to the build-up of excess hydrogen inside the aluminum can, which results in either a rupture of the can itself or destruction of the rubber end-seal. Either failure is potentially catastrophic due to the leaking electrolyte. According to top material scientists in the aluminum capacitor industry, if the correct amount of additives is not mixed into a water-based electrolyte, electrolysis will occur, releasing a high amount of hydrogen gas in the can and resulting in catastrophic failure."
Motherboard Capacitor Problem Blows Up - from Silicon Chip Online's website.
Capacitor failures plague motherboard vendors - Got a failing motherboard that smells bad? You've probably got "burst capacitor" syndrome!
A Computer Whodunnit - A batch of seriously bad components is disabling
computers around the world
It's a
scenario that has played out frequently over the past year, as a rash of faulty
capacitors ÷ battery-like energy-storing components vital to computers ÷ have
leaked or exploded in homes and workplaces around the world.
Smaller than a triple-A battery, these tiny electronic components aren't likely
to cause serious injury to computer users. But a faulty capacitor can render a
computer useless without warning.
And they are ÷ by the thousands, if not millions. Capacitors in all kinds of
electronic circuits seem to be missing some critical ingredients that keep them
from exploding. It's unclear how this bad batch of capacitors came to be. Some
say it's a case of bungled corporate espionage. Industry analysts say that
something like this was bound to happen in such a highly competitive market.
Blown and Leaking
Capacitor failures plague motherboard vendors. Got a failing motherboard that smells bad? You've probably got "burst capacitor" syndrome!
overclockers.com - "How ANYONE Can Replace Leaking Capacitors" Paul Baggio - 4/13/03. But before you decide to have a go, follow the lnik below and click on FAQ's...
This is a great site to learn more about this problem."Most motherboard related failures are due to the "On-board" regulated supplies and component failure within those circuits.I have seen similar capacitor failures on almost every brand and model of motherboard manufactured between 1998 ~ 2001"