Uncontrolled CPU Cooling Fan Speed

Here is the link for all the various support manuals, software and instructions for your PC if you need them; http://h20000.www2.hp.com/bizsupport/TechSupport/DocumentIndex.jsp?contentType=SupportManual&lang=en&cc=us&docIndexId=179911&taskId=101&prodTypeId=12454&prodSeriesId=316713 CPU fans should be plugged into the CPU fan power socket on the motherboard, in order to receive variable speed control instructions. If the fan has been incorrectly connected to a different motherboard fan socket, or directly to the power supply then it will run at a constant speed. If it is correctly plugged in to the correct socket, then the hardware management software (there are many possible options here - please post back with which management software you are using and I can give more specific instructions) that comes with the PC should allow you to change the settings - you can change the temperature range at which the cpu fan will go into higher speed mode - it sounds like you may have this set too high You should also be able to control the fans from the BIOS set-up menu - this should be accessible when you boot up. usually it will be by pressing F8, but all systems are set up slightly differently. watch the screen as you boot up and it should give instructions for this. Hope this helps, please give more details of how your machine is set up if you need more specific help :)

The problem with this model is dust. Remove the fan and heat sink, clean out all the dust. The fan will run at variable speeds again.