Thinkpads Forum

I've just bought a 3-year-old Thinkpad T400s and despite its age I expected it working well, because I read a lot of the famous durability of the Thinkpads.

Unfortunately there seems to be a problem with the overheating. It means I have to underclock the CPU everytime I want a silent laptop. The idle temperatures are at 45 C° in the Balanced mode, but just opening a 480p video in the Flash Player gets it in 52 C° and the fan doesn't stop running at high speeds. I am using TPFanControl and while browsing the net the fan stays in the Fan 3 level all the time, which makes it noisier than all the cheap laptops around. After starting an antivirus scan it takes it just a few seconds to get to 70 C°. I have already tried to blow the dust from the fan with a compressor, but it seemed to be clean. My question is, if the only solution is to apply the thermal paste on the CPU, I am a bit scared of making it wrong.

Another thing bothering me is the fan noise. It isn't a constant humming, the fan rapidly increases the revolutions about every 5 seconds and than they are slowly falling down and this repeats over and over all the time. I noticed this in every Fan Level from 1 to 7. I am concerning about the fan wear after some time.

Any advice would be greatly appriciated

Welcome to the forums.

The pulsing fan behavior is typical of many laptops. It may be a problem with the fan, but that does not mean the fan will die soon. It can stay like this for a long time... (which may be worse, since it's annoying ).

You can tell TPFanControl to leave the fan always at 1 instead of 3, and it will be quieter. Whether it will provide adequate cooling - you can see. There is nothing alarming in temperatures of 52C, and under load 70C is fine too.

You can also tweak TPFanControl more thoroughly to set different thresholds for the fan to start/stop.

A ThinkPad if taken care of with proper maintenance and some degree of 'kids gloves' can last a long long time. There could be one or several factors contributing to the heat generated by your T400s. It could be a mixture of hardware, software, ambient air temperature, and some blocking of the air vents (some users probably do not even know there is a fan in the laptop!).



Can you tell us what BIOS your T400s is currently flashed with?

Also please try using the forum search feature on top of the page near the header for this page. You might find some answers there. I do not have a T400s but I have a T400 which is relentlessly quiet and capable even w/its 2.53 ghz processor despite being a ~4 year old laptop. It is a bit bigger chassis-wise but just saying. Hope you find some answer soon! Happy Holidays

Thanks for replies.

I'm using the latest BIOS version (1.22 from 2012-10-24) and even in the BIOS environment the fan didn't stop spinning fast. I'm using TPFanContol with custom setting:

Level=44 0
Level=46 1
Level=55 2
Level=65 3
Level=73 4
Level=76 5
Level=82 7
Level=92 64

I know there are people who just set the values to 80 C°, but I don't think this is the best ever solution.

How does the fan sound with just the BIOS screen? Does it fluctuate, run loudly, etc?

If it comes down to it and you have to do a reapplication of the thermal compound here are some suggestions

Personally I use Arctic Silver 5 however YMMV. First there are doers and there are don't doers. It is up to you. I remember the first time I had to apply a fresh coat of thermal compound. I was terrified and I imagine it is how a surgeon must feel before performing their first big surgery! I bit the bullet and had went for it. Never regretted it and am almost a pro now

Essentials for disassembly: make the time (may or may not be time consuming), get a good workspace set up, and have good lighting.

1) Download the HMM. Here is the direct link to download it for the T400s. Click here for T400s HMM

2) You will notice in the PDF file that there are diagrams that will instruct you every step of the way to a complete tear down. Make sure you have a way to read the PDF to guide throughout the process of disassembly.

3) Before you start disassembling get some blank sheets of paper (printer/copier sheets will work)

4) You will use the paper to draw a diagram of the areas as you progress through diassembly

5) Remove all power supply from the laptop e.g. the battery, disconnect the AC, and when you get the keyboard and palmrest off disconnect the CMOS battery

6) From this point on using drawings will ensure you do not mix up or lose any screws; some sort of tape might be helpful. I poke the screws through the diagrams and use tape to hold them in place. That way I know where they go and do not end up guessing where a screw goes.

7) When you get down to removing the heatsink you will need to clean the old thermal compound off (your 3 year old thermal compound may look dried out and cake-like in appearance)

8 ) I use coffee filters to wipe the old compound off. For the remaining bits of leftover paste I dab a clean coffee filter into a capful of 91% Isopropyl Alcohol and wipe.

9) as these are electronics we are dealing with make sure any part of the laptop that has been exposed to the Isopropyl Alcohol is evaporated

10) For amount of AS5 you will only need a rice grain size dollop. You will need a clean credit card or razor blade to spread an even and thin layer of the thermal compound across the top of the CPU. Do not make it too thick as we want the thermal compound to fill the microscopic imperfections between CPU and fan exhaust assembly. Making it too thick will result in less efficient heat dissipation.

11) For the fan exhaust assembly make sure you have cleaned the area that will rest on top of the CPU as well.

12) Now reattach the fan assembly to the top of the CPU

13) reassemble your T400s....don't forget to reattach the CMOS battery

lol a little bit of a long post but I realize it can be intimidating doing a disassembly. If anyone has any things to add please do! These days disassembly is nothing new to me. I've done a panel change, removed a motherboard, etc. Practice makes perfect and learning something new is never a bad thing- especially if it is a practical thing

Good luck

Thanks so much for an extremely helpful post

I will try this as soon as I have some time and then I make you know how it worked

I Wish You a Merry Christmas

Before you start disassembling the laptop and buying thermal paste, keep in mind that the temperatures you reported seem completely normal. Not sure what, if anything, you will achieve by replacing the thermal paste. You may have an unusually noisy or somewhat defective fan.

dr_st wrote:Before you start disassembling the laptop and buying thermal paste, keep in mind that the temperatures you reported seem completely normal. Not sure what, if anything, you will achieve by replacing the thermal paste. You may have an unusually noisy or somewhat defective fan.

I agree these temps seem fine. I used a T400s daily as my main laptop and it ran 24/7 for almost three years, these temps are normal. You can set TPFC to reduce fan noise and you should be fine. My idle temp was in the 50's, never the 40's. If however, your fan is actually defective, that is a different matter and you can replace it but if it's a matter of the fan running too often, scale it back with TPFC.