It’s the second time my notebook get to this situation where the cpu fan keep going, and the processor is 100% while the operating system is basically doing nothing.

The main symptom is the one described above, but the real indicator is an event viewer message saying:

“The speed of processor 0 in group 0 is being limited by system firmware. The processor has been in this reduced performance state for 16 seconds since the last report.” ( Source: Kernel-Processor-Power, EventID 37)

Last time I solved it by calling DELL support, which sent a technician to replace the fan. The issue is not related to the fan, but to the dust that get stuck within it. I then decided to solve it by myself this time, since I just don’t want to stay one hour at the phone explaining this thing to DELL another time (just for everybody reference: 5 out of 6 people in my office called dell for this thing… I think someone in their engineering forgot that, beside people working on the construction field, also offices has some minor dust around.. and mine I must say it’s pretty clean.

There what i have done (I suggest you to evaluate if to call dell assistance, and remember that opening your pc you could brake your warranty agreement)

i started from the dell service manual, which can be found here: http://support.dell.com/support/edocs/systems/latd830/EN/SM_EN/index.htm

I started with the Processor Thermal-Cooling Assembly procedure. Once it was completed, I removed the dust within the cooling assembly.

HTH

Alberto