# ThinkPad T420 Fan issue



## Shynn (Aug 11, 2011)

Hi,
Recently I was playing a game that I've played for quite a while and I realized my notebook was heating up more than usual. Ppon closer inspection, I realized that the fan was no longer running. However, when I turn on the intel turbo boost, the fan runs just fine. What can be the problem? All answers are appreciated, thanks.


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## dai (Jul 2, 2004)

check the fan is not clogged with dust


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## Shynn (Aug 11, 2011)

dai said:


> check the fan is not clogged with dust





smuglar said:


> Yep... Dust... And if you keep running it it will loose a few blades and will become really noisy...


It seems like an over night problem though, I was playing the game the day before and it was just fine. Perhaps a chunk of dust got dislodged and clogged up the fan? And if so, how do I get it out? I have a can of air duster but I used it before on a friend of mine's thinkpad and then it encountered a fan error and couldn't even start up so I'm afraid to use the air duster.. 
Thanks for the replies however I really appreciate it


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## Shynn (Aug 11, 2011)

bump
thanks again


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## dai (Jul 2, 2004)

open the access panels on the back and then dust it


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## smuglar (Mar 12, 2012)

Unscrew under the laptop. Then carefully open the bottom cover. Locate fan and using some form of alcohol(methylated spirit) clean the blades of the fan. This type of alcohol is highly flammable so wait for the alcohol to evaporate and your done. Screw everything together and start your machine. 
By the way, there should be perforated outlets on your chasis where hot air is let out. Put your hand there before you open the machine just to check if there is warm air being pushed out of the machine. This will let you know if the fan is working optimally or not.


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## Shynn (Aug 11, 2011)

dai said:


> open the access panels on the back and then dust it





smuglar said:


> Unscrew under the laptop. Then carefully open the bottom cover. Locate fan and using some form of alcohol(methylated spirit) clean the blades of the fan. This type of alcohol is highly flammable so wait for the alcohol to evaporate and your done. Screw everything together and start your machine.
> By the way, there should be perforated outlets on your chasis where hot air is let out. Put your hand there before you open the machine just to check if there is warm air being pushed out of the machine. This will let you know if the fan is working optimally or not.


Thanks guys, I recently downloaded TPFanControl and I noticed something. It seems that my sensors for temperature is not working. I set it to Smart and it does not spin (no fan noise and no warm air coming out as well as heating up) However, it works when i set it to manual ( there's a scale between 0-7 and I input it manually) Just above that, there is a title "Temps" under that I see 
"1 cpu n/a
2 aps n/a
3 crd n/a
4 gpu n/a
5 no5 n/a
6 x7d n/a
7 bat n/a
8 x7f n/a
9 bus n/a
10 pci n/a
11 pwr n/a
12 xc3 n/a"


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## dai (Jul 2, 2004)

run it set on max


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## mahmudaq (May 8, 2013)

Shynn said:


> Hi,
> Recently I was playing a game that I've played for quite a while and I realized my notebook was heating up more than usual. Ppon closer inspection, I realized that the fan was no longer running. However, when I turn on the intel turbo boost, the fan runs just fine. What can be the problem? All answers are appreciated, thanks.


You can clean the T420 fan and vents easily and without voiding its warranty by removing its keyboard. The keyboard is held by just 2 screws underneath. You can find a guide for how to remove it on Youtube. Remember, you don't need to remove more than 2 screws for this: One is the RAM cover plate screw. The other is under the RAM cover indicated by markings on the laptop body.

Once the keyboard is out and you can see the fan, you just need to ensure that the fan does NOT spin while you are blowing dust out. Hold it down gently with your fingers. Use a simple canned air duster with a nozzle attachment and blow air from the fan blades outwards in short bursts. Be careful not to tilt the can too much and get liquid sprayed out. That could cause frostbite and even damage the laptop.

I did this and within 10 minutes my T420's avg temp went from 60-70 degrees C to under 40 C. On load, it still doesnt go above 60 C.


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