Effects of dust and dirt
Components covered in dust run much hotter than they were designed to, and the computers central processing unit (CPU) could start to throttle performance. Throttling is a method used to prevent the CPU from over heating, the computers performance drops significantly for no apparent reason. The computer becomes slow and unresponsive, similar to virus or malware activity. Some CPU's don't utilize throttling and the computer will simply shut off, or Windows crashes displaying a blue screen once the CPU begins to overheat. If the central processing unit does not take steps to protect itself it could damage the CPU. The damage caused by an overheating PC could lead to a myriad of problems, and symptoms making it harder to determine the source of the trouble when the PC is repaired. Thus driving up the cost of repair for a potentially bad computer.
Don't wait until it is ruined to clean it
Dirty fans are loud
Computers with really dirty fans are louder than normal due to the fans having to run at higher speeds in order to cool the components. If your computer has gotten louder over time it is not because it is getting older, it is most likely due to dust and dirt build up. If a computer is throttling or crashing it needs to be investigated. With desktops it is easy just open the case and take a look inside. Laptops are a bit harder and may need to be disassembled to thoroughly clean them. Either way just ignoring the warning signs can possibly lead to a complete system failure. A quick look inside can mean the difference between simply cleaning the PC, or possibly having to buy new parts, or even buying a new computer.
Just like a car over heating a PC will fire up and run again once it has had time to cool. However, once you turn it back on the cycle starts over again. Doing this over and over could potentially ruin the computer causing damage due to excessive heat. Not only potentially ruining the computer, but gradually corrupting the file system which may warrant reloading the operating system to repair the damage.
Fans and heatsinks
Fans are the primary cooling system in most computers. They bring cool air into the case and push warm air out. They also blow air directly onto heatsinks which cool components like the central processing unit (CPU). Heatsinks are finned metal blocks that dissipate the heat generated by the chip they are seated to. The fins allow air to flow through them transferring the heat into the case which is blown out by a case fan. If any of these fans fail the system can become much hotter than it was intended to get. A computer with failed fans may work all winter long and then start to fail badly during summer months.
Don't ignore the inside of your computer case
A plugged heatsink is worthless for cooling, it will get hotter and hotter with the component it is trying to cool. A sign of this happening is the computer becomes much louder as the fan has to spin faster and faster to perform normal duties. Don't ignore a louder than normal computer.
Sometimes fans go quiet as well. If your computer is suddenly quiet that would be a good time to take a look inside. The video card below went with a bang.
An overheating components can become a fire hazard
This vide card went with a very loud bang that was described like a fire cracker. However, the end user needed the computer, so they keep using it until it would freeze or crash. Repeating the process over and over again. The video card got hot enough to change the color of the board from red to brown in spots and by using it the end user risked fire and possibly ruining the computer.
Removing the dust
Fans can get so clogged with dust that they can be rendered ineffective. Fans are constantly forcing dust onto the heatsinks, eventually this build up can stop the fan from spinning at all. It is important to open you computer case and dust the inside once every six months for dusty environments, once a year for normal amounts of dust. People who have indoor pets and or are smokers need to dust more often.
Compressed air cans
When using compressed air cans be sure to keep the can upright to prevent spraying liquefied gas onto your computers components. Cans of compressed air are not good for the environment and can be dangerous due to the very cold gases. Blowing directly against skin at close range can burn very quickly. PCMD recommends a small blower instead of compressed air cans.
Do not try and dust the inside of CD's and DVD players. Do not blow air directly into an open or closed DVD, CD-ROM, or Blu-ray drive to prevent fouling the laser with dust.
This Dell design was an air flow failure
Before you begin cleaning your PC pcmd just wants you to know If you choose to use anything to dust your computer pcmd takes no responsibility if things go wrong. The tips outlined are for information purposes only and do not state that anyone can or should dust their own PC.
Before dusting the inside of your PC unplug the power cord and all peripherals. Never touch any internal components without properly grounding yourself. One way to do this is to touch a metal part of the case before you begin. The best way to be sure you are grounded is to use a grounding strap and mat. Do not proceed with dusting your own computer if you are not comfortable with doing mechanical things yourself or you in any way question what you are doing.
Computers need to be cleaned on a regular basis and if you have more than one it can take quite a few cans of compressed air to effectively clean them. Consider buying a blower made specifically for computers. I would not recommend an air compressor unless you have a properly maintained water trap, and a working pressure regulator. As always use caution and proper settings.