Thinkpads Forum

Hi, my T420s processor is quickly up to 90 degrees Celsius when in 100% power mode, around 50-60 when in 25% power mode set by Windows 7.

How to find out if dissembling and changing thermal grease would make any difference? Any tests/benchmarks to find out how far my cooling system condition is from best could be for t420s?

Thank you!

Most likely a clogged fan.

Take the keyboard off to expose the fan (see the HMM at the top of this page). Hold the fan down gently at the center and then give it a few bursts of compressed air to remove debris and dust.

I'd also like to suggest that you look at your CPU usage when the temps are high.

For my T420s, I had high temps which was being caused by high CPU usage %....turns out the Ricoh media driver was causing some havoc with the CPU usage and in turn stressing out the cpu fan and causing high temps.

I originally cleaned out the fan and removed the old thermal paste (and applied new Arctic Silver 5 thermal paste) but the temps were still high.

Found out after troubleshooting that high CPU usage was caused by the Ricoh media driver and I ended up having to disable the card reader.

This was under Win10 Pro 64bit...

**oops - re-read your OP and you mentioned power save mode...not sure what this exactly and not sure if my high CPU usage comments are relevant**

With all due respect brchan, you may have the T420s confused with another model.
The cpu+fan is at the bottom of the motherboard, so Alex, you'll have to do something like this:

https://www.youtube.com/watch?v=M3aivW-7qJk

You might as well change the thermal paste while you're at it. (I recommend MX-2).
If you have the discrete Nvidia GPU, you'll want to address its cooling issues as well.

I don't know if there are any thermal pads in there for chips other than the CPU and GPU,
but if there are, you'll probably want to change them as well.

With all due respect brchan, you may have the T420s confused with another model.
The cpu+fan is at the bottom of the motherboard, so Alex, you'll have to do something like this:

Good catch; Yes I didn't see the 's' until you mentioned it. Still, it seems you can expose enough of the fan with the keyboard off, but I wonder if it would be safe to use a q-tip to gently hold down one of the fan fins and then use compressed air.

Thank you all.

Actually, I saw already that disassembling my t420s is long complex process, therefore asked that question here. My goal is find some PC load benchmark and advice of owners of 420s what CPU temperatures are normal under which load and decide if changing thermal staff inside is worth it.

I have experience disassembling T410 and after assembling it again its' body is not 'solid' for some reason (some cracks if pushed on cover), so I'll open my 420s only if sure it will make large difference.

IMHO, the temperature of your T420s isn't so abnormal.
My T420s has i7-2640m, NVS4200 either.
Yesterday, I just finished changing old fan module with the brand new one and used thermal paste MX-2 then checked temperature.
The result is almost same with yours. (The quick reach up to 90 Celsius when in 100% power mode, around 50-60 when in 25% power mode)

Hi,
I´ve dealt with the t420s overheating aka noisy fan problem for almost a year now and I think I´ve tried every single magic trick there is in the book, the results = still overheating and a noisy fan. I´ve replaced the thermal paste, bought a new heatsink, disassembled the whole laptop (multiple times, more than 7 times!) and cleaning the dust out of every single corner of the laptop, reset the laptop, used compressed air to clean the heatsink, nothing gives a satisfying result. The results now are -77-82c (when web browsing), over 86c when gaming. Before it was 89c-95c+ when browsing the web. My advice is to buy a t430s heatsink (which just has a quieter fan, but might still overheat or my most reliable advice, to buy a new mother board.

I have the integrated graphics card and an I5

I'm starting to clear my backlog of "real" projects, and am now getting back to my T420s mod.
This morning, I fired up my T420s with i5 + nvidia, and the temps shot up when I used Unison,
which is a file system synchronizer which runs on Linux and does a lot of compression.

Almost immediately, the OS had to throttle back the CPU which had reached 97 degrees C.

Then, I recalled this fairly recent thread on this topic, and someone observed that a
T430s runs cooler: http://forum.thinkpads.com/viewtopic.php?t=122158

Is there a big difference in the fans between the 2 models, or is Ivy Bridge better in this
respect than Sandy Bridge?

Running my T420s, when I max out the CPU (F@H), 100% CPU usage, left all day/week, my laptop never gets into the 90C.
I did change the thermal paste, I made sure the fan stays clean, etc.
With an "upgraded" thermal paste, especially over the stock pads, the temperatures were down.
I just realized yesterday my T420s was reaching 92C on full CPU usage, and for now its on a rest until I clean it. Mainly I want to do some upgrades when I have it apart also. When my laptop is not being used, but just on, the CPU temps are so low that they aren't the warmest thing anymore. Under normal use, my temps are nothing I worry about staying fairly low.

When cleaning, what I noticed to be the main issue of air flow was the little screens on the bottom of the case get clogged.

https://www.dropbox.com/s/cvtp0v8fmldvu ... .04.08.jpg

Here you can see that some of the holes are getting clogged, and some are still open.
I just cleaned the those slots on my laptop while typing this and my temperature is down a few degrees. I still have to clean inside the laptop though.

Core i7-2620M, and NVS 4200M.

I also use the Think Pad Fan Controller with a fairly aggressive cooling set up. Pretty much the fan is never off, gets to max fan speed at a lower temperate, etc. My fan has never been loud at max speed, and maybe the sound has to do with the fan being dirty. But this doesn't change the max temperature the T420s will reach since the fan will always be on the same fan speed by then.