Commentary
2/10/2005
02:50 PM
Fred Langa
Fred Langa
Commentary

Langa Letter: Curing Laptop Overheating

Sometimes, Fred Langa says, fixing a too-hot laptop/notebook computer is as simple as "Whooosh!"



Fred LangaA reader recently sent in this letter:

Mr. Langa: A friend forwarded me your Year-End PC Tasks article, which was very interesting, except it doesn't apply to the millions (OK, maybe not that many) of us who have laptops.

My laptop frequently overheats, and besides buying a new machine, I have no idea what to do.... So what are the options?

Thanks, Samantha

You're certainly not alone, Samantha. When you include all the variants of portable PCs from slender, lightweight laptops up to full-sized "desktop replacement" notebooks, there are tens of millions of units in use. If you also include tiny, handheld PCs, the number goes even higher.

The problem in discussing notebooks and laptops is that portable PCs are much less standardized than are ordinary PCs, which enjoy a high degree of parts and technological uniformity from type to type and brand to brand. It's not just differences in shapes and sizes among portable PCs, but it's that different laptops/notebooks can employ different technologies, different ways to pack components inside the case, different power systems ....

Fortunately, Samantha's letter focuses on one particular issue--overheating--which is one area where a general discussion about laptops/notebooks actually can be quite useful.

You see, all "air-breathing" laptops/notebooks (those that rely on drawing air through the case for cooling) share at least a few similarities: There's usually one or more air intakes through which cool air enters the system; a heat exchanger that dumps excess thermal energy from the CPU or system as a whole into the incoming cool air; and one or more exhausts through which the now-warmed air exits the system, carrying the heat away.

Most higher-powered laptop/notebooks use one or more fans to assist the airflow; it's a miniaturized version of the same type of cooling system found in most full-sized PCs. But some laptop/notebook systems rely on natural convection--warm air rising--to move the air around. These systems still have case openings and an internal heat exchanger, but no fan.

Still other units, especially handhelds and some smaller, standard PCs, have no case openings for airflow. Instead, they use the case itself as a heat exchanger. These units tend to be lower-power to begin with, so they have less heat to dissipate. Overheating is a much rarer issue with these units; and any such problems are usually resolved simply by turning the unit off for a while, or moving it to a cooler spot (e.g., out of the sun).

For this article, we'll focus on the true "air breather" laptops/notebooks; those that have case openings, an internal heat exchanger and (usually) a fan. And, for convenience, we'll refer to this whole class of units as "laptops," even though some of them--"notebook" PCs, to the linguistic purists--are too large and heavy for routine laptop use. Similarly, we'll include "tablet" PCs in the general category of laptops; they fit into today's discussion as long as they have case openings for cooling.

What Causes Overheating In Laptops?
When a laptop gets too hot, the cause almost always boils down to one of three main issues: Dust and dirt blocking airflow through the unit; a dead fan; or environmental causes.

Whatever the cause, the unit can't get rid of its heat, and temperatures climb inside the case. If you're lucky, the laptop's heat-sensing circuits will shut everything down when temperatures reach dangerous levels; you may lose data, but your hardware will probably survive, at least for a while.

If you're less lucky, you'll start getting data errors or lockups. Here, too, you may lose data, but you may be able to save the hardware through a prompt manual shutdown.

In a worst case, or after repeated lesser overheating episodes, your laptop may simply end up cooked to death; either inoperative, or so unreliable as to be worthless.

Of the three main reasons for overheating, the environmental issues are the most obvious and easiest to avoid: Don't use your laptop in full sunlight for extended periods; don't leave it in a closed car on a sunny day; don't place it on or near extreme heat sources, such as radiators, hot air vents, and so on. Common sense, really--and the same advice that's in almost every owner's manual for almost all portable electronic devices. It's so obvious, in fact, we won't spend any more time on it.

The other two reasons--dead fans and dust and dirt--both cause reduced airflow through the laptop. You can look for and solve these problems the same way. Most times, you won't have to open the laptop's case, so there's no issue of voiding the warranty, and nothing that requires exotic tools or training. In fact, it's so simple a procedure, I'm amazed more people don't do it.

Our test case is a high-mileage IBM ThinkPad that's been used almost literally every day for several years.

(click image for larger view)


Our test case is a high-mileage IBM ThinkPad that's been used almost literally every day for several years.
Real-Life Example: Cleaning A Laptop's Cooling System
Consider this test case: An IBM ThinkPad that's several years old. It's my personal laptop; it's used almost literally every day.

As with almost all hardware work, your job will go smoother and be easier if you work in a clean, well-lighted area. Because you'll be peering into small openings on your laptop, you may also find it useful to have a bright flashlight on hand, in addition to bright ambient lighting.

With the laptop shut off (not "suspended," "sleeping" or "hibernating;" but shut down all the way), start by unplugging all cables from the unit, and then remove the battery pack, which usually is on the bottom or in the side of the laptop. (Check your owner's manual for exact instructions.)


With the laptop shut down completely, unplug all cables and remove the battery pack, following the instructions in your owner's manual.

(click image for larger view)

With the laptop shut down completely, unplug all cables and remove the battery pack, following the instructions in your owner's manual.

Start with a thorough visual inspection of all the laptop's case openings, and make a mental note of any dust and dirt accumulations.

First, find the air exhaust, intake, and fans(s), if any. On this laptop, the exhaust is on a rear corner of the case; the intake is on the bottom of the unit, and there is one fan in the intake, blowing cool air into the system. Other laptops place the fan on the exhaust side of the air path, sucking warm air out of the case; still others use more than one fan.

Note the dust on our test system (see photo): Six of the small exhaust openings are substantially blocked with fine, gray dust, and there's more dust visible on the heat sink fins, behind the plastic grill.

Half a dozen of this laptop's exhaust openings show significant dust blockage.
Half a dozen of this laptop's exhaust openings show significant dust blockage.

(click image for larger view)

The intake area also shows visible dust buildup (although it's harder to see in the photo). There's a modest accumulation of dust on the top edges of the fan blades; around the edge of the circular opening; and on some of the plastic grillwork that's directly over the fan.



Several of the intake openings also show dust buildup; and dust is clinging to the leading edges of the fan blades as well.

(click image for larger view)

Several of the intake openings also show dust buildup; and dust is clinging to the leading edges of the fan blades as well.

While the inlets, outlets, and fan are the obvious places to look, be sure to check any and all other openings in the laptop. For example, the docking port opening on our test system shows a light dust buildup.

Laptops often have many openings, any of which may be susceptible to dust buildup. Here, the docking port opening on our test system shows a light dust accumulation.
Laptops often have many openings, any of which may be susceptible to dust buildup. Here, the docking port opening on our test system shows a light dust accumulation.

(click image for larger view)

Similarly, the card slots, network plug openings, floppy and CD drive openings and the like also need inspection: A flashlight or other bright light source may help you peer inside the smaller/darker openings without having to take anything apart. Make a mental note of any locations where you find a dust build-up.


Be sure to check the card slots, network plug openings, floppy and CD drive openings, and so on. A pencil eraser can help open access doors that are too small for your fingers (but don't let the metal ferrule contact anything inside the system). A flashlight or other bright light also will help you to see inside.

(click image for larger view)

Be sure to check the card slots, network plug openings, floppy and CD drive openings, and so on. A pencil eraser can help open access doors that are too small for your fingers (but don't let the metal ferrule contact anything inside the system). A flashlight or other bright light also will help you to see inside.

Laptop hard drives and RAM banks are heat producers, and a layer of dust can act like a sweater, trapping heat inside. If these components are readily accessible on your system, you can carefully remove their access covers to see if any dust is accumulating there. Be sure you only look; don't touch, as these components are static-sensitive.

If you wish, you can carefully remove the access covers for the laptop's RAM and hard drive. These delicate electronic devices are static-sensitive, so don't touch them: Just open the access ports and look to see if any dust is accumulating around these heat-producing parts. (Note: In this and some of the other photos accompanying this article, some personally identifying information on the laptop has been blurred.)
If you wish, you can carefully remove the access covers for the laptop's RAM and hard drive. These delicate electronic devices are static-sensitive, so don't touch them: Just open the access ports and look to see if any dust is accumulating around these heat-producing parts. (Note: In this and some of the other photos accompanying this article, some personally identifying information on the laptop has been blurred.)

(click image for larger view)



Start The Cleanup
Ordinary, clean, dry cotton swabs are fine for much of the cleaning you'll be doing. Later on, you'll be blowing dust out from inside the laptop, so at this step your primary goal simply is to loosen any stuck-on dust or "fur balls" inside the laptop. If necessary (and as shown in the accompanying photo) you can remove most of the cotton from the tip of a swab to access tight spots; you only need a small amount of cotton "fuzz" on the swab tip for effective cleaning of confined spaces. Work carefully and gently; don't force the swab into tight areas.


An ordinary clean, dry cotton swab will work to loosen or remove much of the dust and dirt visible through your laptop's openings. If the full swab won't fit, peel away as much cotton as needed (and as shown here) to reduce the swab's diameter.

(click image for larger view)
An ordinary clean, dry cotton swab will work to loosen or remove much of the dust and dirt visible through your laptop's openings. If the full swab won't fit, peel away as much cotton as needed (and as shown here) to reduce the swab's diameter.

Once the worst of the dust has been loosened or removed mechanically with the cotton swabs, use compressed air to complete the job. (Air carried most of the dust into your laptop; air can likewise remove most of it.) While you can use almost any source of dry, clean air, your best bet may be to use a product designed for the purpose. For example, I used a can of "Dust Off;" it's one of many similar products available at most office-supply and electronics stores. These cans of compressed gases produce highly controllable, highly directional, very intense bursts of dry, filtered air; and usually come with a long plastic nozzle that's ideal for working inside crevices and hard-to-reach places. A can costs only a few dollars and can last for many cleanings. (Read and follow all label directions.)

An inexpensive can of compressed air can help your cleaning immensely by providing highly controllable, highly directional, very intense bursts of air. The cans usually come with a long plastic nozzle that's ideal for working inside crevices and hard-to-reach places. Many brands of ''air in a can'' are available; your local office-supply or electronics store probably stocks several.An inexpensive can of compressed air can help your cleaning immensely by providing highly controllable, highly directional, very intense bursts of air. The cans usually come with a long plastic nozzle that's ideal for working inside crevices and hard-to-reach places. Many brands of "air in a can" are available; your local office-supply or electronics store probably stocks several.

(click image for larger view)

No matter what air source you use, be careful not to overspin the laptop's fan: A strong blast of compressed air can spin a small fan like a pinwheel, over-revving it enough to damage the motor or bearings. To prevent such damage, keep the fan from spinning as you clean it. As the accompanying photo shows, I gently inserted a clean cotton swab between the fan's blades so the fan couldn't rotate when I blasted the blades clean with compressed air.

With the laptop's fan blades secured, maneuver the flexible tip of the compressed air dispenser to access every part of the laptop that you can reach around and through the fan assembly, from every possible angle. And be careful: You may be surprised at how much debris whooshes out with the first few blasts of air!


To prevent mechanical damage to the laptop's fan, keep it from spinning as you clean it: I gently inserted a clean cotton swab between the fan's blades so the fan couldn't rotate when I blasted the blades clean with compressed air.

(click image for larger view)

To prevent mechanical damage to the laptop's fan, keep it from spinning as you clean it: I gently inserted a clean cotton swab between the fan's blades so the fan couldn't rotate when I blasted the blades clean with compressed air.

Note also that some "compressed air in a can" products can spray a supercooled liquid if you invert the can. This is good for neither the laptop nor anything else the liquid may touch; and it actually can cause frostbite on human skin. Once again: read and follow all the directions that accompany whatever compressed air product you use.

Work your way around the laptop, swabbing and blowing out all openings where you previously identified dust buildup.
Work your way around the laptop, swabbing and blowing out all openings where you previously identified dust buildup.

(click image for larger view)

Repeat the cleaning process for all other openings you identified previously. Use care with any openings near the fan to ensure that your blast of cleaning air doesn't spin the fan; if necessary, re-secure the fan with a swab, as before.

When you're done, the fan area and other openings will be clean, clear, and dust free.

When you're done, the fan area and other openings will be clean, clear, and free of visible dust.

When you're done, the fan area and other openings will be clean, clear, and free of visible dust.
(click image for larger view)
(click image for larger view)

When you're done, the fan area and other openings will be clean, clear, and free of visible dust.



Wrapping Up
Replace any covers or access panels you previously removed, and reinstall the battery pack. When the laptop is right-side up, you may wish to use some of your remaining compressed air to blow out the keyboard area. Cotton swabs also can help clean any other cracks and crevices around the screen or keyboard.

You also may wish to use a soft, slightly dampened cloth to wipe down the case and screen; be very careful not to rub hard on the screen, which may be vulnerable to scratching or breaking; and use care not to let any liquid drip into any part of the laptop.

On my laptops over the years, I've had good luck with plastic-treatment products such as "Armor All." Used sparingly (no drips!), it's improved the contrast on my displays by helping to reduce the appearance of the fine scratches that can accumulate on a laptop's screen; these scratches scatter light. After treatment, with less light being scattered, the whole display looks better. But different laptops are made from different plastics, and I can make no guarantees about how your system will respond: If you want to try this, you're on your own: Experiment carefully on an inconspicuous spot before trying a large area, and, again, use extreme caution not to allow any liquid to drip anywhere into your laptop.

When you're done cleaning, fire up the laptop, preferably on AC power, so it will run at full speed and produce maximum heat. Listen carefully: The fans should operate as they did before. For example, if your fans always came on at initial startup, at least for a few seconds, make sure you hear them spinning during this startup. Or, if your fans normally would come on after, say, five minutes of full-power operation, wait the full five minutes to ensure the fans are now working properly.

If they're not, try a simple fix: With the laptop turned on and running, very, very slowly and carefully move it--no sharp jolts or fast, sudden moves!--so you have access to the fan. Using one of your cotton swabs from before, gently nudge the fan blades in the proper direction. Sometimes, that's all a fan needs to get going after it's been stuck: It may then spin normally for a long time to come.

But if not, your laptop needs service; it should not be used with a dead fan, or permanent damage may occur. If your laptop is out of warranty and you're mechanically handy, you may be able to open the case, remove the dead fan, and install a replacement yourself. But if the laptop is in warranty or if you're unsure of your abilities, call for professional help in replacing the fan.

When your laptop is running OK, use a thermal monitoring tool, such as the free SpeedFan utility, which lets you monitor the temperatures, fan speeds, and voltages inside many systems. (Not all SpeedFan features work on all systems, but the temperature monitoring--which is the most-important function--works on the majority of systems equipped with thermal sensors.) A tool like this can help you understand your system's thermal performance; and give you early warning to impending problems in the future.

In any case, with the fans spinning normally, and with your laptop's cooling system now dust-free and unobstructed, your portable PC should now run cooler--and maybe quieter--than before!

What's your take? What tools, tricks and techniques do you use to keep your laptop running smoothly? Join in the discussion!


To discuss this column with other readers, please visit Fred Langa's forum on the Listening Post.

To find out more about Fred Langa, please visit his page on the Listening Post.

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