I recently created a small item elevator that used a comparator in the back of the first dropper to go through a signal with a 2 tick delay than go through to temporarily power the hopper going into the first dropper and also have a 1 tick delay signal to power the dropper, but when I placed a comparator to receive power from dropper 2#, it got no power so I checked in it and it apparently got no items in it yet the chest on top still received blocks.