I put an amd 6000 dual core cpu into a gigabyte mb. The heatsink fan are supplied with the cpu.
I hit the start button on the case the powersupply fan goes, the case fan goes and the heatsink fan goes for a few seconds then stops.
Now i automaticlly think it is faulty so i remove it and take out the cpu so as not to cook it.
I sit the heatsink on the case and hit the power button and the heatsink fan goes perfectly.
So i put the cpu back in put the heatsink back on hit the power button and everything goes except the heatsink fan which did its 2 second rotations and stoped again.
So i take it out again and try it on the case and it goes perfectly.

Then i get a heatsink from a amd 5000 and put the cpu back in attach the fan and it goes perfectly, actually run for hours.
So i take it out and replace it with the 6000 fan and back to square 1.
Any suggestions?