Icnoaparition 0 Posted February 19, 2005 After installing my new heatsink my cpu constantly turns off. I went to Directron.com on their website they show you how to install it on the very bottom it shows a fAQ on it says exactly what i put down awhile ago.This is what it says The Bios of some mainboard manufactures compares the speed of the fan with specified value.If the speed does not match the specific value ,either Pc emits a warning or switches off.Con- trary to the temperature control,the RPM control is of no importance since fan speeds will be between 500 and 7000 Rpm depending on the type of fan.This Rpm control can deactivated in the BIOs setting.Please Instead activate the temperature warning.This protects your cpu also from other cooling problems than failing fan. In the case of the Pc is not booting or immediately switching off,attach the plug of the cooler to auxiliary power of the main board and attach a second fan with a higher RPM to primary power socket.Now the pc can boot allowing the RPM control to be deactivated in the bios setting. We recommend using a temperature ctrl instead of a rpm cntrl. I don't know anything about computer will some tell me step by step what to do.Plz. Share this post Link to post