[ltp] Weird CPU fan problem on T400, any help appreciated.

[Mark Altern]

It is set as automatic all the time.  Playing with BIOS is the first 
thing I did after I found this problem.

On 07/17/2010 04:49 AM, Jason Brooks wrote:
> Sounds like a issue with the acpi driver (maybe a bug or setting
> passed to the kernel is missing).
> Try setting the bios to automatic instead of performance or max battery.
> Jay
> On Fri, Jul 16, 2010 at 7:55 PM, Mark Altern<mark.altern@gmail.com>  wrote:
>    
>> Before Ubuntu 10.04, I was using 9.10 and the cpu fancontrol is working OK,
>> without me installing any fancontrol software. I think the BIOS control it
>> through acpi. It works perfectly.
>>
>> Now after I did a clean install of 10.04, I found the BIOS doesn't do it
>> correctly: since the start-up cpu fan speed is about 1886rmp (normal), when
>> the cpu temp goes to 55c, it cramp up to 2700rmp, then after that even the
>> cpu have been idle for a long while and temp drop to 37c, the fan wouldn't
>> slow down, but keep running at that high speed.
>>
>> Then as suggested by a linux guru friend, I use a Window 7 install DVD to
>> boot the laptop without doing anything, and then reboot back to Ubuntu
>> 10.04, this time the CPU fan start working correctly, meaning the fan speed
>> goes up and goes down according to cpu temp. BUT, this lasts only for a
>> short while, and after running it for a hour, the CPU fan will run high
>> speed (2738rmp) without slowing down again, even the CPU temp drop to 36C
>> already.
>>
>> What possibly is wrong? please give me some guidance, guys.
>> Thanks a lot.
>>
>>
>> Lenovo Thinkpad T400,
>> p8600@2.4Ghz, DDR3@4G, 160G@7200RPM, Intel X4500.
>>      
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