The Mycosynth Gardens copies exactly what was printed on the original artifact and nothing else (unless that permanent is copying something else; see below). It doesn't copy whether that artifact is tapped or untapped, whether it has any counters on it or Auras and Equipment attached to it, and so on.

If the copied artifact is copying something else, then The Mycosynth Gardens becomes a copy of whatever that artifact copied.

If the copied artifact has {X} in its mana cost, X is 0.