There’s nothing like a few days in the high 80’s or 90’s to put your computer or laptop’s cooling system to the test. Of course if you have good air conditioning, this all may go unnoticed, but for those who don’t, or if you use your laptop on the road, outdoors, or in public places like classrooms, buses, or subways, rising temperatures outside means rising temperatures inside your computer that could become so critical your system shuts itself down to prevent damage.
How does cooling work in the PC?
Your computer’s processor (CPU) generates enough heat in a tiny space, that left uncooled, it would cook itself to death in a matter of minutes, To counteract this, system designers have come up with a variety of schemes to draw heat away from the CPU thus ensuring that it is sufficiently cooled to operate reliably. Most CPUs are air-cooled by the combination of a heat-sink (a heat-conductive metal structure designed to draw heat away from the surface of the cpu chip) and a fan that pushes air through the heat sink structure and exhausts the air along with excess heat out through vents in the computer chassis. You can usually locate these exhaust vents on a laptop just by moving your hand around the back and sides of the unit until you feel a gentle rush of warm air exiting the case. In most cases, there are sensors that measure the temperature of the CPU and cause the cooling fan to run faster when the chip gets hotter, and slower when the chip gets cooler. The purpose of this fan speed regulation is to balance the cooling needs of the CPU with the aesthetic need for the computer to run quietly and not be a noisy intrusion in the room.
A COMMON SYMPTOM: NOISY FAN
Understanding how cooling works, it’s easy to see how the first sign of a cooling problem is usually that the cooling fan suddenly becomes very loud, and remains on and running at high speed for prolonged periods of time. This is a dead giveaway that your computer is fighting to stay cool, and in most cases, is losing the battle!
I once had a customer who told me her computer sounded like an airplane trying to take off. While we had a good laugh over her description, it was no joke when I opened the tower and found the cooling system so clogged up with pet hair and dust that it was a wonder any air was passing through it at all!
In this case, the cause of cooling failure is usually blockage of the air vents or the “fins” on the heat sink where the fan is trying to push air through. This is remedied by using a vacuum or compressed air (or both!) to clean out the vents, the area around the heat sink and fan, as well as any cowling that may be in place to direct airflow. This can get very messy and is generally recommended to be performed outdoors so you don’t end up blowing all that accumulated dust and stuff into your indoor breathing space.
What if your PC abruptly shuts down before it even finishes booting up?
I have observed, particularly in older desktop PCs (windows xp vintage), that sometimes plastic clips used to join the heat sink to the CPU surface can become brittle and break causing the heat sink to “pop” off of the CPU. In this case you may get the high-speed fan sound, but more importantly, the PC may freeze up and become completely unresponsive or more commonly, it may abruptly shut down within 30 seconds to a minute of being started. If this happens, don’t keep trying to start it! More than a few times starting without the heat sink attached and the CPU will cook itself leaving you with little choice except to go shopping for a new computer.
What if your fan isn’t noisy but you get a warning message indicating an overheat situation, or your pc shuts down abruptly without warning?
It’s not always the case that cooling problems are indicated by a noisy fan. In fact, a cooling problem could also be indicated by a suddenly quiet fan that used to be noisy or an least noticeably running. In this case, your fan may have failed and is either barely turning, or has stopped altogether. In this case, the computer may issue an error messsage, but is more likely to just abruptly shut down without warning after a few minutes of operation. In this case, the fan usually needs to be replaced.
One time, I was called in to a local dry cleaner to investigate why their computer kept shutting itself down. When I got there, I found a portable tabletop fan pointing straight into the back of the computer and running at full speed. The manager said this was the only way he could get it to run without shutting down. Not surprisingly, when I opened the unit up I found it so packed with lint, there was no airflow at all from the built in fans. That customer is now on a regular regimen of quarterly cleaning to avoid the inevitable lint buildup.
Other signs that a cooling problem may be looming on the horizon…
Groaning – If your computer is making what is described by many customers as a “Groaning” sound, this usually indicates the bearings are wearing out on the cpu or graphics cooling fan. Replace the fan now because if you just ignore it, rest assured, when the groaning stops, so will your computer!
Pets – If you have pets (including birds), particularly breeds that shed a lot, expect your cooling vents to get plugged up quickly. Plan on a vacuuming/blowout at least annually, more often if you notice a marked increase in fan speed/noise.
Dusty House – If you’re like me and live in an older or antique house, you know that it’s a constant battle to stay ahead of the pervasive dust that seems to be shed endlessly by horsehair plaster. Thanks to its constant airflow, your computer’s cooling system is like a magnet to plaster dust and should be blown out at least annually, more often if you notice increased fan activity or are undergoing home renovations that generate inordinate amounts of dust.
I’ve given you a few different computer overheating scenarios, some that are easy to remedy, and some that may require professional help. The most common failure, the clogging of vents and heat sink with dust, lint, or pet hair, is forunately also the easiest to tackle on your own if you’re a do-it-yourselfer. Go to Staples and buy a couple cans of compressed air and use it to blow dust, hair, and other obstructions from your computer’s vents and fans. But don’t forget, do it outdoors unless you relish the thought of breathing in a dust cloud!!!