Ram not Working

[buymeonly99p]

Ram slots 3&4 are not working :/
i just fitted a corsair h55 on to a asus P8Z68-v pro motherboard with a i5 cpu i have double checked all the cables and pins, and i have use compressed air on the ram housing still nothing :/
Any one got any ideas??

 

[Vic 40]

Maybe reattach/reseat the cooler.If one side presses to much on that side of the cpu and the memory controller is placed there is it possible that this does not work properly.