X20 fan ALWAYS running

[harob]

Hello forumites!

I recently bought an X20 over eBay, and it's working perfectly except for one thing: the CPU fan is always on. It starts running at full speed as soon as I power on, and never stops.

So far I've tried:
- Two BIOSs and Embedded Controller firmwares (the latest ones and the earliest ones which run WinXP)
- Windows 2000 and Windows XP
- Installing all the ACPI/power management drivers from the IBM website
- Opening the laptop, removing the CPU heatsink, cleaning, and replacing the thermal paste.

Mobilemeter reports a CPU temperature of between 25 and 35 degrees C after startup, and PCDoctor claims the Fan is working correctly, so I can't see how it could be a hardware problem.

Any help would be really appreciated, as it's embarassing to use the laptop in public for now.

[dmdsoftware]

Some suggestions:

1) Remove the mini-pci card and test the system. How long does it take for the fan to kick in?

2) Install IBM BatteryMaximizer tool.
a) Create a profile that utilizes the CPU at "very very slow" (for ac and battery). Activate the profile. How long does it take for the fan to kick in?
b) Create a profile that utilizes the CPU at "fast" (for ac and battery). Activate the profile. How long does it take for the fan to kick in?

If your fan just will never shut off, your motherboard might be malfunctioning. During the POST, the fan turns on for a brief second while the system tests to make sure it's a-okay. It sounds like it just isn't going back off after that brief test. Do you ever see the fan cutting out even for a brief second?

[harob]

Thanks for your reply.

I've just tried removing the PCI card, but it didn't change anything.

The fan has never cut out at all; it kicks in as soon as I push the power button, and stays on at a regular speed.

[harob]

This seems to be a rare problem; it would appear to be frequent with the T series, but I haven't found any info dealing with it in the X series.

Is there really nothing I can do?

Would it be conceivable to just unplug the fan? (I only use the laptop for presentations andword-processing)