Some readers whose personal computers were randomly restarting and constantly "freezing" decided to open it to take a look inside and, to their great surprise, they discovered that the capacitors of the motherboard had leaked. In some extreme cases, the capacitors had literally exploded.
Electrolytic capacitors are components used in the tension regulating circuit of the motherboard, that is, they help in the conversion of the feeding source tension into the tension with which the processor is effectively fed. Thus, if the capacitors are defective, defects such as the ones described happen (notice that those symptoms also happen for several other reasons, that is, if your personal computer is restarting on its own does not necessarily mean that there is a defective capacitor in its motherboard).
A motherboard with defective capacitors can be visually idenfied. The upper part of the capacitors, usually straight, made of aluminum, gets "swallowed" upwards. When it leaks, you can see the electrolytic liquid that is usually inside the capacitor around the defective capacitor, often corroding the motherboard. And, in extreme cases, as we commented, the capacitor may literally explode.
Figure 1: Leaked capacitors on a motherboard.
But why does this happen? According to the site from TTI Inc (http://www.ttiinc.com/object/ME_Zobgi20021014.html), there was a group of electrolytic capacitors made in Taiwan with low-quality electrolytic material (seemingly without the additives required to evaporate the excess of hydrogen gases from that material). It seems that 11 manufacturers of electrolytic capacitors bought that low-quality material, making those capacitors that leak and explode after some use.
Contrary to what may be thought, that is not a problem affecting only manufacturers of low-quality boards. Several well-known manufacturers like Soyo, Abit and Shuttle, only to name a few, seem to have used those explosive capacitors in their motherboards.
Similarly, that is not a problem affecting only computer motherboards. Cellular telephones, notebooks and videocassette recorders that used those low-quality electrolytic capacitors were also affected.
The solution for that problem is the substitution of the defective electrolytic capacitors of the motherboard, cleaning it properly with isopropyl alcohol before the installation of the new capacitors. That is a task that any electronic technician is capable of performing, so specialized labor is fully available on the market.