Ever since i have got my motherboard and cpu i have had problems trying to attach the heat sink stably as i can not get the pins to go in fully if the one diagonal to it is in.
is there any way to tell if its my motherboard preventing it to be attached or whether its the heat sink itself
To mount the Intel stock cooler properly, place the motherboard on top of the foam or cardboard backing that was packed with it.
The stock cooler will come with paste pre applied, it looks like three grey strips.
The 4 push pins should come in the proper position for installation, that is with the pins rotated in the direction of the arrow,(counter clockwise) as far as they can go.
Place the cooler so that all 4 pins are oriented over the holes in the motherboard.
The trick to getting it on is to push down on a diagonal pair of pins at the same time. Then the other pair.
If you do them one at a time, you will not get the cooler on straight.
Lastly, look at the back of the motherboard to verify that all 4 pins are equally through the motherboard, and that the cooler is on firmly.
This last step must be done, which is why the motherboard must be out of the case to do the job.
It is possible to mount the cooler with the motherboard mounted in the case, but you can then never be certain that the push pins are inserted properly.
If you should need to remove the cooler, turn the pins clockwise to unlock them. You will need to clean off the old paste and reapply new if you ever take the cooler off.