Take a look at our
ThinkPads.com HOME PAGE
For those who might want to contribute to the blog, start here: Editors Alley Topic
Then contact Bill with a Private Message

Fan error t420

T400/T410/T420 and T500/T510/T520 Series
Post Reply
Message
Author
polowsky
Posts: 3
Joined: Fri Aug 17, 2018 1:32 pm
Location: Wroclaw, PL

Fan error t420

#1 Post by polowsky » Fri Aug 17, 2018 1:49 pm

Hi guys!
Unfortunately I have faced problem with Fan error. I disassembly keyboard and generally fan won't start.. I was trying to touch the fan, make it run but with no result. So I ordered new fan, replaced, put together everything but still the same message.. So again I disassembly keyboard - and ... now fan is starting and then stopping :/ I am not able to run over it with ESC or even get in to BIOS.. Do you have any idea what is going on? Motherboard died? Did someone had the same problem?

RealBlackStuff
Admin Emeritus
Admin Emeritus
Posts: 23809
Joined: Mon Sep 18, 2006 5:17 am
Location: Loch Garman, Éire

Re: Fan error t420

#2 Post by RealBlackStuff » Fri Aug 17, 2018 2:28 pm

Welcome to the Forum.

If fan and thermal paste are in good condition, then usually the fan will only run for a few seconds at boot, then stay off until the CPU gets hot.
Did you clean/refresh the paste when you replaced the fan? Instructions: http://www.arcticsilver.com/pdf/appmeth ... d_v1.1.pdf
Lovely day for a Guinness! (The Real Black Stuff)
Lenovo: X240, X250, T440p, T480, M900 Tiny.

PS: the old Boardroom website is still available on the Wayback Machine
.

polowsky
Posts: 3
Joined: Fri Aug 17, 2018 1:32 pm
Location: Wroclaw, PL

Re: Fan error t420

#3 Post by polowsky » Sat Aug 18, 2018 3:14 am

Yes, it wasn't my first time with changing fans, cleaning laptop "interior" etc.. But I took off one more time radiator and fan, cleaned old paste and put the fresh paste... with the same result :( I think heatsink abut properly to processor because pipe is warm after these few seconds between pressing start button and Fan Error message.

RealBlackStuff
Admin Emeritus
Admin Emeritus
Posts: 23809
Joined: Mon Sep 18, 2006 5:17 am
Location: Loch Garman, Éire

Re: Fan error t420

#4 Post by RealBlackStuff » Sat Aug 18, 2018 7:03 am

You could try to buy/borrow/replace the CPU, although they rarely fail.
But if yours already gets hot in a few seconds, something is not quite all right.

Few more things to try:
check that you have no passwords in BIOS, then switch off, remove charger and battery.
Hold down the Power-button for about 20 seconds (discharge any capacitors/reset laptop).
Now also remove yellow CMOS battery for a few minutes.
Put CMOS back, then only charger and try to reboot.
Fan now working?

polowsky
Posts: 3
Joined: Fri Aug 17, 2018 1:32 pm
Location: Wroclaw, PL

Re: Fan error t420

#5 Post by polowsky » Sun Aug 19, 2018 3:35 am

Still the same :( doesn't work - now I have also message about wrong time/date ") - it is regarding second part of your post.
I will try to replace cpu, Do you think that the hot pipe is caused by a damaged processor?

RealBlackStuff
Admin Emeritus
Admin Emeritus
Posts: 23809
Joined: Mon Sep 18, 2006 5:17 am
Location: Loch Garman, Éire

Re: Fan error t420

#6 Post by RealBlackStuff » Sun Aug 19, 2018 8:16 am

Date/Time is kept by the CMOS battery, just reset it in BIOS, that's all.

If you remove the fan (again), does it look as if the whole CPU-surface and the whole matching part on the heatsink are evenly covered in thermal paste?
If only a part of the heatsink is covered in paste, you may have a warped heatsink.
What did the old fan/heatsink look like?

And yes, a poorly mounted heatsink, OR a bad CPU, might cause almost instant overheating.
So try another CPU if possible.

toreroerba
Posts: 1
Joined: Tue Oct 25, 2022 11:13 am
Location: Rome eternal city Italy

Re: Fan error t420

#7 Post by toreroerba » Tue Oct 25, 2022 11:20 am

Hy my friends @polowsky and others, Have you good news about this problem? I m going to buy a new or used fun, but i seriusly think that I cant solve my problem with this replacement.
I also try to replace cpu but nothing, also reset bios unplugged internal battery but after message of CMSO date change still appear FUN ERROR and stop the machine.
Please suggest me something
:wink:

98497
Posts: 1
Joined: Sun Dec 18, 2022 1:10 am
Location: oslo, norway

Re: Fan error t420

#8 Post by 98497 » Sun Dec 18, 2022 1:16 am

Hi. I was having a similar issue with the fan starting but then stopping 1 second later after booting. This caused the CPU to run hot and shut down, then reboot, repeating indefinitely.
In my case disabling the security chip in BIOS seems to have stopped this. My laptop only stayed on for 10-15 seconds at a time so I had to be fast, but I was able to go into BIOS, disable security chip, save and exit. And it seems to boot, with the fan running. I am not sure what caused it but I'm assuming my security chip is faulty. Long shot but I'm just posting this in case it helps someone else.

It does cause TPM communication error to have it disabled which is annoying. But at least it boots.

Post Reply
  • Similar Topics
    Replies
    Views
    Last post

Return to “ThinkPad T400/T410/T420 and T500/T510/T520 Series”

Who is online

Users browsing this forum: No registered users and 43 guests