[ltp] Re: pwm controls in /sys

Henrique de Moraes Holschuh linux-thinkpad@linux-thinkpad.org
Sat, 27 Apr 2013 22:17:03 -0300

On Sat, 27 Apr 2013, Dave Cunningham wrote:
> Are those RPMs too low?  Does this mean I need a new fan?

Your thinkpad needs repair, yes.  But it may not need a new fan.  Have you
cleaned it up yet?  The two common defects that cause this are: (1) dirt,
and (2) cracked thermal interface.  (2) is far more serious, a recurring
problem on thinkpads (especially if you ever handle it in any way that
causes even minute flexes of the mainboard, such as holding it with just one
hand) and you must repair it as it slowly damages it for good.  OTOH, both
are relatively simple repairs.

To repair (2), you need to remove the heatsinks, remove all the old thermal
compounds, and replace them with an extremely high performance compound
(Arctic Silver 5 is one I can recommend, but others that are medium to
high-viscosity, *non* reactive, *non* conductive _and_ as good or better at
thermal conducitivty will also work).

To repair (1), remove the keyboard and blow the lint away, hold the fan
stopped while at it as it is not a good idea to spin it at extreme speed,
and that can easily happen while blowing the lint away with compressed air.

  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh