ESD Protection (continued...)

    Although static buildup can’t be completely eliminated, there are precautions you can take to reduce the possibility of damaging components due to electrostatic discharge. You should always ground yourself to discharge any static buildup before touching anything inside your computer’s case.

    Warning: You should never open the case on a power supply or monitor unless you are qualified to do so and know exactly what you’re doing. You do not want to be grounded if you’re working inside a power supply or a monitor. There are capacitors inside these units that store enough electricity to stop your heart (even when unplugged). You should not open the case on a monitor or a power supply. Please note that this is important enough to tell you twice.

Antistatic Wrist Straps   
An excellent way to prevent ESD damage to your computer is to use an anti-static wrist strap. It’s a conductive strap that fits on your wrist as you’re working. It has a wire attached to it with an alligator clip on the end to connect to your case or to an anti-static mat. Some can be plugged right into the wall socket. Only the ground receptacle makes contact. But make sure the cord is long enough, unless you have a receptacle right at table level. If you’re working inside a computer’s case, the most important tool you should have is an anti-static wrist strap.

   Note: A piece of wire wrapped around your wrist and attached to the case does not work the same. Anti-static wrist straps have a resistor inside and are designed to slowly and safely bleed charges away.

    At the very least, you should use an anti-static wrist strap
connected to the bare, unpainted metal of your case’s frame. There are two schools of thought on this subject:
    One is to leave your computer plugged in. Any static buildup is discharged along your wrist strap to the computer's case, then through the power cord into the ground receptacle of your electrical outlet.
    The second is to unplug your computer. With the wrist strap attached, this should put you and your computer at the same potential charge and no transfer of electrons should take place.
    This becomes a decision you have to make for yourself. A lot of books will suggest that the computer remain plugged in, and in fact, the A+ Certification exam considers this the correct choice at this time (which is probably why these books suggest it). However, when you leave the computer plugged in, it’s a little too easy to turn it on when you’re working inside; or forget it’s on and plug in an expansion card or drop a screw onto the motherboard. Also, you have full AC power going to the remote power switch on the front of your computer. If there is a bared wire, or open contacts on the back of the switch, you could get quite a shock. Remember too, that today’s ATX motherboards have power to them even when the switch is off.

A very good alternative is to plug your wrist strap right into the ground receptacle of a wall socket, or into a grounded antistatic mat.

Antistatic Mats
    Antistatic mats provide a grounded surface on which to work or place components as you remove them. They also have a cord that can be plugged into a wall outlet to slowly remove any static charges. Some come with another cord and a clip that attaches to your computer’s case. The computer does not necessarily have to be on the anti-static mat when you’re working on it. If the mat is plugged into a wall socket then it’s grounded. Attach an alligator clip from the mat to the case, and now the case is grounded. Attach your wrist strap to the case, and now any static buildup can be safely discharged from your body. As you are working, any parts you remove or plan to install, can be safely placed on the anti-static mat.

    If you find yourself in a situation where you don’t have a grounding mat or anti-static wrist strap, then you should keep one hand on a bare, unpainted portion of the chassis as you’re working inside the case. This method is not that reliable and you’ll soon find it to be a little awkward. The ten or twelve dollars spent on a good wrist strap is a wise investment.

What else?
    Don't work on a computer or components when they are cold. Allow them to warm up to room temperature first. Cold, dry conditions promote static electricity. In the winter, when it's very dry, static can build up very quickly. Raising the humidity in your workplace can help to dissipate this buildup. Humidity at 50% to 60% is ideal.
    Keep components and expansion cards inside their anti-static bags until you are ready to use them. Remember to handle them carefully, by their edges and as little as possible. Anti-static bags are treated to be conductive so that they draw static away from the components inside. It's always a good idea to keep a supply of anti-static bags to put expansion cards and components into when working on a computer.
    It's better to have a tile floor in your work area than rug or carpet, which promotes static buildup. Also, think about what you wear. You don't want to be working inside your computer while wearing a wool sweater or a nylon jacket.

    You may not be able to take every ESD precaution all of the time, but use your head and do what you can. The components and hardware inside your computer are subject to electrical fluctuations, spikes, surges, power losses, temperature extremes and, I suppose, even physical abuse. But, the number one cause of damage to internal components is Elecrostatic Discharge.