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Clean Your Machine: How To Remove and Clean A Heat Sink

Posted on March 16, 2009 by admin

heat stink!

Cleaning is an important,  and often overlooked,  part of maintaining a computer for optimal performance and longevity.  Just one look at the poor fan & heat sink to the left should be of some inspiration to any of us that own a computer.  Now, you may be thinking “Who could let their computer become so dirty?” True…common sense would prevail that such poor care would lead to all kinds of problems.  However, since most people never actually look inside there computers, dust accumulates over time and is often overlooked until it is too late.

Over time, dust can prevent one or both of your fans from working, causing your CPU and/or motherboard to overheat.  Operating a computer at temperatures of 60°+ can eventually burn out the CPU (computer death!). Luckily computers do have some lines of defense that can protect them against overheating- some are even programmed to shut down automatically when the CPU temperature reaches an unsafe level.  This was luckily the case for my computer (though it ran at temperatures exceeding 85° before shutting down!).

NOTE: There are many diagnostic software programs, such as SpeedFan or Core temp, that are designed to monitor your computer’s temperature (though you can also check the temperature in the system BIOS without additional software).  Make sure that you have a way of accurately taking your computer’s temperature.

Once I finally realized that dust had not only claimed the life of my PSU’s fan but was also causing my heat sink to literally lose it it’s cool, I knew that I had to bust some dust or my computer was going to bite the dust soon!

I did my research on PSU’s and eventually bought a new one, which I installed without a hitch.  Refer to my article “How to pick and install a new power supply unit (PSU) in your computer” for more information on how I found and installed my PSU.

Next, I did a little research on what I would need exactly to clean my heatsink.

NOTE: Not all heatsinks are the same.  Some heatsinks, such as my Zalman model, are encased in a plastic frame and need to be removed to clean them.  However other heatsinks can be cleaned without removing, due to their more open architecture.

You won’t need a lot of fancy tools but you will need several things: a small Phillips head screwdriver, 99% pure isopropyl alcohol, Q-Tips, and thermal conductive grease (such as Arctic Silver or Coolaboratory).

Next,  I needed to consult my computer’s manual and online support to find out exactly how my heatsink needed to be removed- it is not always straight forward and can be different for every model.  However, If the fins are in plain sight and can be reached, you may not even need to remove the heatsink to adequately clean it (depending on how dirty it is).

NOTE: Never attempt to open or work on your computer until it has been turned off and unplugged.  Always touch a metal part of the case to ground yourself before attempting to handle any part of the mother board as the static electricity built up in your hand can easily destroy the delicate circuity.

As for my Zalaman Model CNPS5700D-Cu, I first unplugged the fan, removed the four screws, and cleaned the fan blades gently using alcohol and Q-tips:

an older Zalman fan & heatsink

…then I removed the metal pressure clip (in the middle):

under the fan lies the heatsink (notice the tiny slits, called "fins" where dust can accumulate)

…and finally I flipped open the plastic encasing to remove the heatsink (shown upside down):

a dirty heatsink (old grease)

NOTE: Some heatsinks are actually glued to the CPU and require freezing or other special methods to clean them that I am not particularly aware of.  Proceed with caution!

Next, I took the heatsink out of the plastic encasement to clean out the dust that had accumulated in between the fins with Q-Tips and 99% pure isopropyl alcohol.  After the fins were clean, I placed the heatsink back in the plastic case and proceeded to clean the old grease off the smooth bottom surface.

NOTE: Be sure to use 99% pure isopropyl alcohol rather than the 70% you typically find at the store.  The 70% contains water which is not computer-friendly! Besides, the purest alcohol dries much quicker.

a clean heatsink

After cleaning the heatsink it was time to clean the CPU. The CPU also had old grease that needed to be thoroughly cleaned off.  Once again, I took my trusty Q-tips and alcohol and proceeded very cautiously to clean the surface of the CPU (remember to ground yourself to the cabinet first):

a dirty CPU (old grease)

a clean CPU

Once The CPU was clean, it was time to apply a fine layer of Thermal Grease to the CPU.  You do not need much at all. Put just a little bit in the middle (even less if you are using the expensive stuff) and then spread it around to make a very thin and even layer (using your finger with plastic pulled tightly over it works well).  It is a common mistake to put too much grease, which could pose problems such as short-circuiting the motherboard.  Then again, not enough grease, and you can get hot spots. Thin and thorough does it!

thermal grease applied thin and evenly

Next, I put the heatsink back (being careful to set it down perfectly flat, to keep the grease as level as possible).  I then reassembled everything in reverse order and finally reconnected my fan cable and the job was done!

My computer has not overheated once since I cleaned the heatsink and replaced the PSU.  In fact, it’s been operating at a low-to-high of 35-50°, even under the most intense multitasking conditions and has been performing like an entirely different machine- processing speeds are through the roof! My computer has a new lease on life thanks to a little research and elbow grease (as well as Thermal grease, of course!).

Don’t be too quick to assume that viruses & adware are the cause of your computer woes.  Remember to check your computer’s temperature if it starts to display unusual behavior.  And, last but not least, be sure to Clean Your Machine!