An important part of hardware preventive maintenance is to keep the computer case and internal components clean. The amount of dust and other airborne particles in the environment and the habits of the user determine how often to clean the computer components. Regularly cleaned or replaced air filters in the building in which the computer is used will significantly reduce the amount of dust in the air.
Dust or dirt on the outside of a computer can travel through cooling fans and loose computer case covers to the inside. When dust accumulates inside the computer, it prevents the flow of air and reduces the cooling of components. Hot computer components are more likely to break down than properly cooled components. Most cleaning is to prevent this accumulation of dust. Figure 1 shows a cooling fan that has accumulated an excessive amount of dust.
When dust accumulates inside the computer, it prevents the flow of air and reduces the cooling of components. Several components are important to keep clean:
- Heat sink and fan assembly
- Adapter cards
- Power supply
- Internal drives
To remove dust from the inside of a computer, use a combination of compressed air, a low-air-flow ESD vacuum cleaner, and a small lint-free cloth. The air pressure from some cleaning devices can generate static and damage or loosen components and jumpers.
You can use a low-air-flow ESD vacuum cleaner to remove collected dust and materials from inside the bottom of the case. You can also use the vacuum cleaner to pull in the dust blown around from the compressed air. If you use compressed air from a can, as shown in Figure 2, keep the can upright to prevent the fluid from leaking onto computer components. Always follow the instructions and warnings on the compressed air can to keep a safe distance from sensitive devices and components. Use the lint-free cloth to remove any dust left behind on the component.
CAUTION: When you clean a fan with compressed air, hold the fan blades in place. This prevents overspinning the rotor or moving the fan in the wrong direction.
Regular cleaning also gives you a chance to inspect components for loose screws and connectors. Look for things that might cause a problem later and correct them, such as the following:
- Missing expansion slot covers that let dust, dirt, or living pests into the computer
- Loose or missing screws that secure adapter cards
- Missing cables
- Loose or tangled cables that can pull free from the case
Use a cloth or a duster to clean the outside of the computer case. If you use a cleaning product, do not spray it directly on the case. Instead, put a small amount onto a cleaning cloth or a duster and wipe the outside of the case.