Avoid Static Damage to Your PC, If you're upgrading your PC, static electricity can cause real damage. But a few precautions can protect sensitive electronics.Stan Miastkowski, special to PCWorld.com All of us are familiar with walking across a rug, reaching out to touch a doorknob, and getting zapped by a charge of static electricity, what's technically known as electrostatic discharge, or ESD. For most of us, it's annoying; for some, dangerous (fireworks and explosive makers have to take special precautions to avoid static sparks); and for the sensitive electronics inside a PC, static can be a computer-killer.
For most day-to-day PC use, static isn't much of a problem, but the chances of problems go way up if you pop open your computer's case to add RAM, upgrade your CPU or hard drive, or plug in a new sound card or graphics.
A little background: Static electricity is much more common than you might think, and most of it is created by a process called triboelectrification, when two materials touch (your fingers and your PC keyboard, for example) and then move apart or rub. Electrons are exchanged, and one object becomes electrically positive; the other electrically negative. When you touch another object with an opposite charge, or a ground (neutral charge), electrons flow.
The amount of voltage involved in static electricity sounds impressive. Walk across that rug and touch a grounded metal object, and the voltage can be in the 10,000-to-12,000-volt range. (If you think back to your high school physics class, you'll remember why static voltage isn't life threatening. Its amperage is miniscule. And it's amps,
not volts, which are dangerous.)
There are many variables involved in how much static voltage triboelectrification creates, including the materials involved and the humidity. Low humidity causes static shocks with more kick. But for PC upgrades, the important thing to remember is that while a static shock must be 3500 to 4000 volts before you can feel it, it's the voltage below that level that is common, and insidious. It's entirely possible that you'll open up your PC, plug in an add-in card or some RAM, never have any sensation of static, and still have zapped the electronics. That's because the integrated circuits can be damaged or destroyed by static voltages as low as 400 volts.
What's worse is that the component you installed may appear to be fine, but days, weeks, or months later your PC may lock up or start acting strangely. A dead board or RAM module is easy to diagnose if it doesn't work immediately after you install it, but low-voltage static charges can also cause latent damage, destroying a few gates out of the millions in a typical integrated circuit. That damage can be almost impossible to diagnose, and may not cause problems for a long time. It's also quite possible that you might never take precautions to avoid static and yet never lose a component to static damage.
To avoid the ravages of static damage, your body and the components you're working with (add-in card, RAM, PC case, and so on) must be at the same electrical potential. And the easiest way to do this is to make sure that all static charges are drained to ground, an object connected to the Earth, which can harmlessly absorb the static charge. Until recently, that wasn't difficult. Since all standard AC wiring includes a common ground, you used to be able to ground yourself by touching the case of your PC while it was switched off but still plugged into the wall outlet. However, since today's PCs have voltage flowing through their motherboards whenever they're plugged in (5 volts direct current are used for switching the PC on and off), it's all too easy to accidentally short something and zap your motherboard, without static being involved at all. That's why it's essential that PCs be unplugged when you work with them.
If you're daring and careful, you can still keep yourself and the computer at the same electrical potential by constantly touching the case while installing an upgrade, but it's a juggling act. And if you accidentally touch something with a different electrical potential--such as the tabletop the computer is sitting on--all bets are off.
Using a ground is still the most effective way to minimize the potential damaging effects of static electricity, although you'll need to invest in some additional components Here's how to do it:
•Check your AC wiring: Before you can use the electrical ground in your home or office, you need to make sure it's actually working. Old homes may have grounded outlets on the wall, but they may not be grounded. And even new construction isn't necessarily safe, given the time constraints of harried builders. The best way to check the wiring is to buy a wiring checker. Sophisticated units can be expensive, but Radio Shack has a $20 tester (Catalog # 910-5501) that will tell you if
the ground is working, and much more. If you do find problems, call a licensed electrician to fix them. While they're usually used for bathroom and kitchen AC outlets, Underwriter's Laboratories, the leading U.S. safety certification organization, suggests you have a licensed electrician install ground fault circuit interrupters on all your AC outlets.
While their main purpose is to prevent life-threatening shocks if problems develop with the ground in your AC wiring, they're a logical upgrade for your computer-upgrade work area, because they shut the power off completely if the ground isn't working.
•Use a wrist strap: The easiest way to dissipate static electricity is to use an antistatic wrist strap, which connects to your AC ground. Follow the manufacturer's instructions carefully to connect it. Wrist straps are available in a wide variety of models, fro
m disposable units for under $10 designed for one-time use , to $50 units designed for those who use them regularly. Sources include ESD Systems, Radio Shack, and Visiflex Static Solutions. If you don't want to deal with a ground, $39 cordless wrist straps, based on a technology that uses the Corona principle to dissipate static without using a ground, are also available at Directron.com. Industry experts say they're not as effective as a true grounded wrist strap, but they're better than taking your chances.
•Use additional antistatic components: If you work with computer upgrades regularly, consider investing in additional antistatic measures, such as grounded pads that you can lay your PC case on when you work with it. (You should still use a wrist strap.) The companies listed above have a wide range of products to choose from.
•Prepare your work area: Make sure the area where you're working on your upgrades isn't full of other static-inducing components. A bare table is best. Keep plastic desk accessories, wastebaskets, and telephones away from your work area. And one of the worst creators of static charge is a rolling desk chair. Push it away, and stand up when you're working on your PC.
•Control the humidity: The lower the humidity, the more likely it is that damaging static charges will build up quickly. If your ventilation system allows you to control it, a humidity level between 35 and 50 percent is ideal. If you can't cont
rol your humidity, don't do upgrades on a cold winter day when the humidity tends to be very low, or on a warm day with the air conditioning turned up high. If you live in an area where the humidity is generally high, it's not a bad idea to open the windows while you do your upgrades.
While the precautions above can't guarantee to prevent static electricity discharge, they will at least reduce the chances that your memory or hard drive upgrade will leave your system permanently damaged.
Make sure to let me know in the comments below or on our Facebook page how you’ve got on with it, or you have any questions.
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