Issue: CPU fan on Lenovo Thinkpad T520 is always on.
OS: Ubuntu 10.04.3 LTS Lucid Lynx with backported kernels from Oneiric.
Source used for solution: Ubuntu Forum , — thanks to user mejo
Solution:
1. install thinkfan package:
$ sudo apt-get install thinkfan
2. add kernel module ‘coretemp’ to /etc/modules
$ sudo sh -c ‘echo coretemp >> /etc/modules’
3. load kernel module ‘coretemp’
$ sudo modprobe coretemp
4. add the following three sensor entries to /etc/thinkfan.conf just before the temperature levels:
sensor /sys/devices/platform/coretemp.0/temp1_input
sensor /sys/devices/platform/coretemp.0/temp2_input
sensor /sys/devices/platform/coretemp.0/temp3_input
sensor /sys/devices/virtual/hwmon/hwmon0/temp1_input
[ edit the file /etc/thinkfan.conf with your favourite editor, e.g. ‘sudo gedit /etc/thinkfan.conf‘ ]
5. add the following to /etc/modprobe.d/thinkfan.conf: ‘options thinkpad_acpi fan_control=1’
$ sudo sh -c ‘echo “options thinkpad_acpi fan_control=1” >> /etc/modprobe.d/thinkfan.conf’
6. reload kernel module ‘thinkpad_acpi’
$ sudo modprobe -r thinkpad_acpi
$ sudo modprobe thinkpad_acpi
7. set START=”yes” in /etc/default/thinkfan
[ edit the file /etc/default/thinkfan with your favourite editor, e.g. ‘sudo gedit /etc/default/thinkfan‘ ]
8. start thinkfan:
$ sudo /etc/init.d/thinkfan start
9. check whether it works
$ sudo cat /proc/acpi/ibm/fan
if level has a value between 0 and 7, and changes by times, your thinkfan daemon works.