P150HM mysteriously stuck at 800MHz

I've been using my P150HM for 6 months now and it has been working fine until today, when the cpu clock apparently locked itself at 800 MHz.
The cpu is a quad core i7-2720QM that until now would happily work at ~3000MHz while there was work to do. What I've tried so far:

* Cold reboot
* Flashing with the latest BIOS (1.01.14) and EC firmware (1.00.13)
* Checking the BIOS for any setting that might be off, but found nothing that looks relevant
* Booting with an earlier version of the OS (In case I had installed something funny)
* Checking the cpu-clock while all cpu cores are busy working (since the OS normally should use a low power-saving clock when system is idle)
* Ensuring that I run on plugged-in power rather than battery
* Verifying that the system is using the "ondemand" cpu-speed governor (which should change clock depending on current load)
* Trying the "performance" governor instead (i.e. "always use the maximum cpu clock")

I'm using the i7z tool to get continuous updates on the cpu clock for every core, and I don't think it is misreporting the speeds as benchmark results and amount of fan noise is consistent with an 800MHz clock.

What else could I try?
(Using Ubuntu 11.10)

 

Do you have dual boot where you can try it on Windows?

 

sounds like some power-management-tool is keeping the cpu in powersaving mode (thus the 800 Mhz). do u have the hotkey tool installed? tried to put everything into performance mode? (OS & tool-wise)

cheers

 

derp had this happen to me last month, remove the battery and reboot without the battery in, it should fix it.

http://forum.notebookreview.com/sager-clevo/641303-2630qm-low-clocks.html

 

Resetting the CMOS battery is the panacea to problems like this.

Pull out battery, press power button for 10 seconds, then insert battery and power cord and then boot.

 

Thanks guys, the pull-out-the-battery trick worked!