Hi. My HD 6870 fan wont stop running at full speed. Can anyone tell me why or what I can do to change this. Have changed the thermal paste and looked over the PCB. Nothing visably wrong. Has the fan a built in fan controler or does the fan motor set the speed according to the temp. Please help me sort it out. Thanks to anyone who takes the time to read this and maybe come up with a solution to this funny problem.