This is not a failure as your title suggest. The Fan is slowing down and speeding up because of a technology called Cool 'N' Quiet this throttles the processing power to match the system needs to save on power. To disable this feature go into your control panel and under power options select home/office if this feature is already selected or this does not work you can try disabling it in your bios menu. You can monitor the operation of this feature by downloading AMD power monitor
. Check your owners manual for information on disabling this feature. I am trying to download the manual.
Edit: Received the Manual. The option is under the Advanced menu under AMD K8 cool 'N' Quiet. You want to change it from AUTO to disable. Page 90 of the PDF user manual found here
Edited by Sneakycyber, 16 February 2008 - 12:08 PM.