Weird R40e (2684-HVG) fan problem!

[epeli]

So, I have this old R40e TP laptop. Its fan has stopped working some time ago - It just spins once on bootup etc.


I decided it's time to finally fix it! Sidenote: My TP has been idling around 79°C a lot, sometimes it heats up to 100°C... and the CPU still works! Go go IBM.
Thus I open up the laptop, remove the CPU heatsink and give some voltage to the fan. It worked. I cleaned the fan and put the heatsink back, making sure the fan has room to spin freely.

Ok, I put the laptop back together and the fan back in, but it's still not working. After a bit of googling, I ended upgrading BIOS to 1.38 and EC to 1.04. No effect.

More googling. Found & installed tpfancontrol, which yields somewhat weird results. When I set the fan speed to 0-14, it does nothing. Setting it to 15-64 makes the fan spin once whenever tpfancontrol cycles. 128 causes "couldn't set fan state" error.
Also, tpfancontrol randomly reports "couldn't set fan state/cant read status" and I have no other software that should interfere with tpfancontrol. Otherwise it works well, it reports temperatures and fanspeeds correctly.

Long story short: Fan does not spin when installed, but it seems to be working physically. Thermal sensors are working. BIOS & EC have been upgraded to latest.

Any ideas what could be wrong? Any similar experiences? Don't tell me the mobo is broken.