When i use my L512 at almost idle (just some browsing), the fan is off most of the time, but kicks in every 10-20 seconds. It kicks in to around half speed and then rapidly slows down to around 800rpm, keeps spinning for 15seconds. Then it stops again. This pattern continous the whole day and its very annoying.

I removed the fan assembly and cleaned it. My bios version is 1.37. Windows 7 x64 pro.

I tried all settings in power manager (max cpu speed: maximum/adaptive, system cooling: passive/active)

the core temps (by core temp and speccy) are: core 1: 38-41 deg celcius core 2: 25-28 deg celcius

Tried TPfancontrol, but not sure what the correct settings are, and got sudden sleep problems.

any ideas how to change the fan behaviour?