Electrostatic Discharge (ESD)

Do you always get this “shock” whenever you touch metal things? Well if you did what you had was an Electrostatic Discharge or ESD

Electrostatic discharge (ESD) is the sudden and momentary electric current that flows between two objects at different electrical potentials. The term is usually used in the electronics and other industries to describe momentary unwanted currents that may cause damage to electronic equipment.

ESD is a serious issue in solid state electronics. Integrated circuits are made from semiconductor materials such as silicon and insulating materials such as silicon dioxide. Either of these materials can suffer permanent damage when subjected to high voltages, as a result there are now a number of antistatic devices that help prevent static build up.

source: http://wikipedia.org

One of the main victim in computer parts of ESD is… The Memory Module. The average person can carry up to 25,000 volts of static charge at any given time. This sounds like a lot, but because the current level is low, you usually won’t notice it. And IC’s in memory module has a low voltage requirement that’s why whenever you had an ESD and touched a Memory Module you just destroyed your Memory Module.

There are ways to prevent this:

1. It is a good idea to buy an anti-static wristband, and follow the instructions for use.(They are sold at most electronics stores.) If you are going to do quite a lot of bench work, you might do well to invest in an anti-static mat.
2. If you don’t have a wristband, you are not necessarily out of luck. Assuming that your PC is grounded, you can ground yourself by just keeping one hand in contact with the bare metal frame (not a painted or coated surface) of the computer case. Keep the PC power cord plugged in to a (3-prong) grounded outlet and turn off the rocker switch on the back of the power supply. If the power supply does not have a switch on the back, this won’t work, however. Never work on a PC with the power on. In that case, you should buy an anti-static band or try another method of grounding.
3. As an alternative, alter a standard 3-conductor power cord by snipping off the two flat blades, leaving only the grounding portion of the plug. Or simply purchase a cord like this from an electronics supply house. This accomplishes the same thing as turning off the rocker switch.
4. You can employ an LCD Static Discharger. As a simple measure, you can hang it on your key ring and just dangle it. This is less reliable, but when it touches a ground, it should discharge the static electricity. Procedure：①Lightly touch the oval button with a finger. ②Make sure that the end of the conductive material touches a grounded conductor. (such as vehicle, human body, computer, metal or other) to release static electricity, and observe the LCD display.

If you don’t take steps to prevent ESD, you may regret it. Your computer can sustain serious damage without you knowing it. CPUs and memory chips of any kind are highly vulnerable to ESD. If you fry your PC with static electricity, you may soon start to notice random memory errors, blue screens, and lock-ups. Normally, you can’t see (or even feel) ESD, but it is almost always there, so be sure to do the right thing. Your PC will thank you!

Try not to open up computers on thick carpets, petting long-haired pets, dressing, emptying the dryer, etc. Use common sense; don’t do anything that would cause you to get a shock from touching something made of metal.

source: http://wikihow.com