Diagnosing fan problem

Jesse Sheidlower jester at panix.com
Fri Feb 16 15:11:06 UTC 2007

On Thu, Feb 15, 2007 at 09:24:04PM +0100, Tore Lund wrote:
> Jesse Sheidlower wrote:
> > I have a ThinkPad T41p that has had a variety of fan problems
> > for some time. After my most recent repair things seemed to be
> > working fine, but the other day I was compiling some ports and
> > the machine just shut down in the middle; after some
> > experimentation it seemed clear that it was just overheating
> > under load and shutting itself off. (Looking at the
> > temperature sysctl showed that it was getting increasingly hot
> > until it crashed.)
> > 
> > How can I monitor what is happening? Are there any ways I can
> > find out from FreeBSD if the fan is even on, or how it thinks
> > it is working? "systcl -a | grep fan" didn't return anything.
> There are quite a few programs that can tell you CPU temperature and fan
> speed, like mbmon and conky, both in /usr/ports/sysutils.  You could
> compare these parameters against data for the fan and cooler in order to
> ascertain whether anything is wrong with the fan.

Unfortunately these don't work, or rather they don't report the
fan speed. (In conky, for example, if I add lines to the config file
to report the CPU temp, fan speed, and fan state, I only get the
CPU temp, with the other lines empty.)

> > Can I control the fan?
> I don't know.  In any case, I would not try to control fan speed if the
> problem is that the fan is insufficient or out of order.

Right; my intention wasn't to control the fan manually for
regular use, but rather to try to turn the fan on high so that
I can see if there is, in fact, a whooshing sound that would
indicate the fan has been turned on high.

I'm running FreeBSD 5.4-STABLE, by the way; I acknowledge that
there is the acpi_ibm.ko thing under 6.x, and perhaps this would
be helpful. However I can't even think about upgrading because
compiling almost anything causes the computer to crash from
overheating :-/

Jesse Sheidlower

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