Ubuntu 8.04 running Thinkpad fan all the time
I am having fan / heating issues with my Thinkpad.
I'm using a Thinkpad t61 with Ubuntu Hardy 8.04.2 with Kernel 2.6.24-23-generic. (I have tried both 32-bit and amd64-bit kernels. The result is the same).
I opened the laptop and cleaned the fan. There was no major dust build up. I blew the system out anyway and the fan performance is the same.
This never happened before when using Ubuntu 7.10 32-bit. When I switched to Ubuntu Hardy 8.04.2 it happens all the time.
My machine now constantly spins the CPU-fan on and off. It will spin up to blow for about 60 seconds, turn off and wait for 60 seconds, and then spin back up to blow some more.
This happens within 10 minutes after booting. It does not matter whether the machine is 100% idle or whether it is doing 100% work. The fan starts to spin and continues.
My temperatures are kept around 38C when idle by the fans. During work it manages around 45C, which is 10C warmer than the average (around 35C) before this started to happen.
An interesting observation: The fans never seem to spin at 10% or 50% speed, but always at 100% speed. This might be a contributing factor.