sensors-detect doesn't find fans on HP ProBook 6560b

The fans on my HP ProBook 6560b are almost always running on full speed, venting out hot air all over the place. The fans aren't recognized by lm-sensors and thus can't be controlled eg. by fancontrol (see attached output of sesnors-detect):

sensors
acpitz-virtual-0
Adapter: Virtual device
temp1: +73.0°C (crit = +128.0°C)
temp2: +86.0°C (crit = +128.0°C)
temp3: +43.0°C (crit = +128.0°C)
temp4: +59.0°C (crit = +128.0°C)
temp5: +31.0°C (crit = +128.0°C)
temp6: +0.0°C (crit = +128.0°C)
temp7: +0.0°C (crit = +128.0°C)
temp8: +0.0°C (crit = +128.0°C)

radeon-pci-0100
Adapter: PCI adapter
temp1: +85.5°C

coretemp-isa-0000
Adapter: ISA adapter
Physical id 0: +74.0°C (high = +86.0°C, crit = +100.0°C)
Core 0: +73.0°C (high = +86.0°C, crit = +100.0°C)
Core 1: +74.0°C (high = +86.0°C, crit = +100.0°C)

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: lm-sensors 1:3.3.1-2ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-35.55-generic 3.2.34
Uname: Linux 3.2.0-35-generic x86_64
ApportVersion: 2.0.1-0ubuntu17
Architecture: amd64
Date: Sat Dec 22 00:20:16 2012
InstallationMedia: Kubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111011)
MarkForUpload: True
ProcEnviron:
 LANGUAGE=en_US
 TERM=xterm
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: lm-sensors
UpgradeStatus: Upgraded to precise on 2012-04-29 (236 days ago)