Working Inside the System Case
As we mentioned earlier (and will mention again), never work on an open computer chassis without first disconnecting the power cable from the system. Unplug it completely; don't just rely on switching off the power. The following sections discuss some other things you should keep in mind when working inside your computer.
Take off any jewelry, including rings, watches, and bracelets. Don't wear loose clothing or dangling items such as ties or necklaces that can hang down or catch inside the case. Almost everything mounted on a circuit board has a sharp edge that can snag clothing or jewelry, not to mention the edges of the boards themselves.
Keep Track of Parts
This is a mustyou have to keep track of every screw you remove from your system. Every screw. Keep count, just like medical surgeons do with sponges, so you know you've accounted for them all at the end of the operation, er, upgrade.
First, you must screw back whatever you take out. We've worked on computers that had the hard drive hanging by one lone remaining screw because the others had been lost at one time or another. Second, you don't want to have loose metal screws rolling around inside the computer chassis where they might become lodged across things that have current running through them. You also don't want them getting stuck in heat sink fans.
As you remove screws during an upgrade, place them in an ash tray, on a piece of doubled masking tape (which keeps them from rolling away), or in a small plastic film canister. The small boxes you get from the bank with a batch of checks make great containers for small parts, too.
If you do drop something into your system, be sure to retrieve it. But don't start fishing around inside the case with a magnet trying to remove a dropped screw. Magnets and computers are a huge incompatibility. You want to get a parts grabber (also known as a parts retriever or holder), which looks similar to a pencil. You push one end and a set of small wire claws pops out of the other end, enabling you to carefully snatch a small object out of the inner recesses of your system (see Figure 3.6).
Auto parts stores have longer articulated versions of these parts grabbers, but this is overkill for most computer users.
No Food or Drinks
Don't eat lunch while you're up to your elbows in the system case. If you need a cup of coffee, step away from your work area or leave the room entirely to avoid the temptation (and possible disaster). Ditto while you finish that ham on rye. You don't want to drop crumbs or liquid inside your computer case under any circumstances.
No Fast Moves
The working space inside your computer's chassis is very limited. The electronics parts are somewhat fragile, and sharp protrusions abound. Move around inside the case slowly and deliberately. Don't apply forcefor example, to loosen a too-tight screwunless you're properly balanced and can apply the force in a manner that won't cause a disaster if the screwdriver slips. A screwdriver scraping across your motherboard can ruin it in a heartbeat. Barking your knuckles on a drive cage is not much fun, either.
Don't force things in general, especially circuit boards. Some substantial pressure might be required to pop a board into or out of its slot, but be very careful not to twist the board or to apply pressure unevenly. It's important that you not crack the board you're installing or the motherboard that supports the slot into which you're plugging it. A circuit board is made of an epoxy material (which is somewhat brittle) to which various electrical gizmos are attached. These gizmos are all wired to each other by traces on the board. These traces look like spidery silver lines on some boards. If you crack a board by bending it, you can sever one of these traces and thus ruin the board.
Static Electricity and What to Do About It
Everyone's familiar with static electricity; you reach for a doorknob and just before you touch it, a spark leaps from you to the metal knob and you feel a small zap. This is called an electrostatic discharge (ESD). An ESD is caused by your acquiring a surplus of electrons. Given a chance, nature likes to keep things balanced, so those electrons will leave you if they can by jumping to something else. Something conductive such as the doorknob or a computer circuit board or chip is attractive to the surplus electrons. Zap, indeed.
Off the Wall - Clearing the Static
We once worked in a high-rise office building that caused ESD outbursts that were positively painful. It got to where you hated to open a door because you knew you were going to be shocked. We learned that if we laid the palm of our hand on the door for a moment before opening it, the door would gently draw off enough electrons so that we did not get shocked when we touched the doorknob.
You must be grounded to not have a negative electrical charge when you work on your computer. When you're working on a computer, avoid those leather wingtips and don't shuffle your feet on the carpet. Try a pair of sneakers instead. Touch something that's grounded, but not the chassis of the computer on which you're working because after you unplug its power cable, it is no longer grounded.
Another Fine Mess - Danger, High Voltage
You acquire electrons by touching things. Dry atmospheric conditions increase your chance of acquiring electrons. Leather-soled shoes shuffling across a carpet are notorious for this, and you can produce quite a spark when you touch a conductive surface. It's best that this conductive surface not be inside your computer. That little static electricity zap you feel is caused by high-voltage electricity. No fooling, very high-voltage electricity. Several thousand volts is common; even the smallest spark requires 500 volts or so, which can ruin the delicate silicon chips found everywhere inside your PC. Rub a balloon on your head to the point where your hair starts standing on end and you'll be carrying a charge of tens of thousands of volts. This is not to be taken lightly when dealing with electronic components.
An electrostatic discharge wrist strap is a handy thing to have if static electricity is a problem (see Figure 3.7). It consists of an attachment that makes contact with your wrist (with a conductor wire) and a cord you attach to something grounded. This enables any static buildup to flow from your wrist to ground. The problem, of course, is finding a ground near to where you're working. Remember, the computer on which you're working isn't grounded after you unplug the power cable so it is not a candidate as a ground. We mention this again because it's a common mistake.
The best (albeit not cheap) solution we've come across is a receptacle analyzer carried by some electronics industry tool supply companies. It's a small gizmo that plugs into a three-prong wall outlet and lets you know whether you have a good ground. You plug your wrist strap into the analyzer, which is in turn plugged into the wall. It can feel a bit scary the first time you plug this wire hooked to your arm into something that's plugged into your wall outlet.
Tecra Tools sells a number of static defense tools, including the Stat Gard Receptacle Analyzer, wrist straps, static dissipating mats, and more. Their Web site is http://www.tecratools.com/.
If you think you'll be inside your machine enough to justify the $40$50 expense, this is a good option. Otherwise, be very mindful about static, try to work in an uncarpeted area, and ground yourself to something before you even begin unpacking your upgrade components.