Board Thread:Questions and Answers/@comment-86.167.247.181-20130217123152/@comment-6294495-20130217190155

Does the side of the filter have an animation when the signal is pulsed? If not you may have to provide a valid destination for the diamonds or something may be in the filter's internal buffer that cannot get out, which clogs it up. To clear out this buffer, simply place an empty chest next to a tube connected to the filter or remove the tube attached to the output. Also, make sure there isn't a non-diamond item in the filter's GUI inventory.