Nearly all Mac models employ one or more internal cooling fans. Without them, your computer would overheat, leading to crashes, erratic behavior, and possibly even permanent damage to sensitive components.
But as the fans pull air into the computer, they also pull in dust. Dust can accumulate on the air intake vents, on the fan itself, or on any surface along the flow of air within the computer. When a layer of dust sits atop a hot component, it acts as an insulator, preventing some of the heat from escaping into the air. And if dust blocks the air flow, the heat that does escape has nowhere to go. Either way, your fan must work harder, which not only makes it noisier but also makes it suck in even more dust.
In short, dust is no friend of computers. By the simple act of getting rid of the dust, you can make your Mac cooler and quieterand prevent all sorts of unpleasant problems.
You can remove dust by brushing or wiping, by vacuuming, or by blowing it off with compressed air. The compressed-air approach is the least desirable, because it puts the dust right back into the air. I prefer an ordinary vacuum cleaner with a hose attachment, but before using such a vacuum on the inside of your computer, take note of the warning just ahead. If you choose the brushing or wiping approach, be sure to use a soft, dry cloth or a soft, dry brushand a gentle touch.
Warning! Conventional AC-powered vacuum cleaners, particularly those with plastic nozzles, can in theory build up enough static charge to damage your computer's circuitry if used on the inside of a case. For vacuuming the inside of a computer, use either a battery-powered vacuum or an antistatic vacuum designed expressly for cleaning electronic equipment. In any case, be careful not to touch the nozzle to any components inside your computer.
To de-dust your Mac, follow these steps:
Shut down and unplug your computer; also unplug any peripherals or other cables.
Be sure you have room to work in. If your computer is located under a desk, for instance, move it out into the open.
Using your dust-removal tool of choice, remove dust from in or around any holes or slots on the outside of the case. Be aware that some of these openings may be on the bottom or the back of the case, depending on the design.
These remaining steps are for desktop computers only:
Following the instructions that came with your computer for installing RAM or other internal options, carefully open the case. The method for doing this varies widely from model to model. For example:
Most Power Mac models have a side panel that you can remove without tools by opening a latch.
Remove the back cover of iMac G5 models by placing the computer face down on a soft cloth and loosening three screws in the grill on the bottom.
For iMac G4 models, turn the computer on its side (again, using a soft cloth to protect the display), and loosen the screws on the bottom plate.
Some iBook and PowerBook models have removable keyboards or other ways to access the innards without performing major surgery. But even if you can see part of the computer's insides, you're unlikely to be able to reach spots where dust might accumulate. My advice is to leave the inside of a portable Mac alone; if you have reason to believe you have an internal dust problem, find an authorized service technician to open up the computer and clean it for you.
Once again, remove any visible dust using your tool of choice. If your Power Mac has add-in PCI or video cards, be sure to remove the dust from them as well. (In some cases, you may need to remove the card from the computer, de-dust, and reinsert it. If you do remove a PCI card, be sure to ground yourselfideally, by wearing an antistatic strapwhile handling it.)
Warning! Be extremely careful when removing dust from the inside of your computer! If using a vacuum cleaner, avoid touching the hose tip or brush to any surface. If using a brush or cloth, apply the gentlest pressure possible.
Close the computer's case, reattach peripherals and other cables, and turn it back on.
Warning! Avoid the temptation to perform any further disassembly on your computer beyond merely opening the case. As a general rule, if you have trouble reaching some spot inside your computer, so does dust.