Did you know that dust can act as a weak conductor of electricity? This is something my dad taught me a long time ago while working under the hood of a car, taking care to clean the surface and leads of the battery off so that it was spotless. He said that if dust were allowed to build up on top of the battery it would eventually discharge the thing and you wouldn’t be able to start your car. Granted, it might have to sit for a few days for that kind of problem to occur but it does occur, and similar problems can happen with computers. In fact I’ve encountered a few computers that had dust built up inside of them for a long time which did result in the CMOS battery discharging. This caused a problem if the power went out because the role of the battery is to keep track of the time, date, and a lot of other hardware settings in the BIOS. If these are forgotten, you’ll get a couple errors messages when you turn your computer on after the power has gone out and your computer will think it’s the year 1980-something.
In the last month I’ve fixed three different computers just by blowing dust out of them. These systems would turn on, reach the POST screen (which typically is the logo of the manufacturer or the BIOS) but would just hang there indefinitely. Blowing the system out with a can of air (or in one case an air compressor) was all it took to bring the systems back to life. Dust is just as much of a problem for laptops, but not so much for getting the motherboard dirty (because they’re fairly well sealed off from the outside air) but for clogging the heatsink fins so that the cooling fan can’t push air past the fins to keep your CPU cool. The side effects of this are a noisy laptop that runs hot, or even powers itself off abruptly as a failsafe.
All CPUs these days have internal temperature sensors with a threshold for a certain amount of heat. If that threshold is exceeded the processor will either throttle itself down in speed to the point where the system runs far slower than usual or the BIOS takes over and just shuts the system off completely. So if you have a hot, noisy laptop that shuts off every now and then, you probably need to go buy a can of air.
You’ll find cans of air in the electronics section of just about any major retail store. You need to be careful with these things because they contain a liquid that itself can conduct electricity and short your electronics out. To prevent the can from shooting this stuff out it’s important to always hold it level and upright, not sideways or upside down. This liquid also has an extremely low boiling point, which causes it to feel very cold when it’s not under pressure. You can feel this by touching the can after using it for a little bit, and even hear the liquid boiling away inside to replenish the can with more compressed gas. Something fun kids like to do with this stuff is spray it at glass while holding it upside down to produce a cold frost on any surface. So you need to be careful not to do this to your own skin by accident or you might get a little frost bite.
These things can go pretty quick so I like to shoot the air in short bursts to try and save air while maintaining higher pressure. Be sure to use that little straw that comes with these things to get a more focused shot of air into the areas that need it most. I would also recommend you do this outdoors as the dust particles could make you sick if you inhale them. Be sure to shoot everything, especially the inside of the power supply (that grey box your power cord plugs into) from all sides.
On laptops the only thing you can really dust out is the heatsink and your keyboard. Some laptops have exhaust vents that only come out the back of the laptop, while others come out the side. What I like to do is position the laptop in such a way so that I can shoot air directly into this exhaust vent against the normal flow of air produced by the fan while the laptop is running. Having the laptop on while you do this is a good thing because the fan will help blow dust you’ve loosened back out and also help break it apart into smaller particulates that can fit through the fins. Also shoot air into the intake of the fan. Go back and forth between the exhaust and intake a few times until you can’t produce any more dust with your air. Just beware that if you have never done this before you might have so much dust built up on the backside of the heatsink that loosening it up might cause a large chunk to get wedged in the fan, preventing it from spinning. This isn’t much of a problem if you can remove the bottom panel from the laptop to access the intake of the fan but not all laptops let you do this and you might have to dismantle the entire machine to reach the fan and pull the fat dust bunny out with some tweezers.
I like to keep a can of air in the glove compartment of my car so I’ll always have something on hand to clean a system out when I make house calls. But you should keep a can nearby and clean your system every 3 to 6 months to help improve air flow in your system so it can stay cool as well as reduce the possibility of something important being shorted out.
Saturday, May 21st, 2011