T420S fan error

[bluetomgold]

My son's T420S won't boot up past BIOS. It displays "fan error". I can't hear the fan running.

The fan had been noisy for a while... I ignored it.

We started dismantling following this video https://www.youtube.com/watch?v=M3aivW-7qJk but I just wanted to ask for advice before it gets too involved.

Looks to me as if it's unlikely to be something simple - fan turns easily by hand, doesn't feel as if it's a lubrication issue - it's also fairly clean - I'm kind of assuming a new fan is the solution and replacing it seems relatively long-winded.

Before I get too involved is there anything simple to check first?

And if I need a replacement fan, any pointers on what to buy? Are generic replacements OK or would an older "reconditioned" unit be better? I'm guessing i'll need some thermal paste too...

Pointers gratefully received. The last time I attempted fan replacement on a Thinkpad (my old T61) I somehow managed to inadvertently blow up the GPU...

Incidentally, he's sat next to me doing his maths work on a T41 running Xubuntu.

[bluetomgold]

Haha. i just put it loosely back together and powered up. All ok. No error and the fan is running silently... Maybe giving it a little push was all it needed?

He just gave me a high five, but i'm not sure we've cracked it yet.

teeheehee

[RealBlackStuff]

Nowadays I recommend Phobya NanoGrease Extreme thermal paste.
Available e.g. on https://www.aquatuning.co.uk/thermal-pa ... treme-3.5g

Nowadays I recommend Noctua NT-H1 thermal paste. [update 08/2021]

If you need to spend less, alternative could be Arctic MX-4 e.g. on https://www.amazon.co.uk/ARCTIC-MX-4-20 ... ref=sr_1_3

Pasting instructions: http://www.arcticsilver.com/pdf/appmeth ... d_v1.1.pdf

[bluetomgold]

Cool, thanks.

For the time being it seems to be working fine so I haven't investigated further.

Perhaps worth buying the bits for when it finally does pack up...