Water, run the humidifier longer.
These look so dry, though, that the roots may be dead. Put water in your bathtub and stand these in there for an hour or more. The water should be about half way up the pot. If you pour water on top now, it will just flow down the sides and not wet the substrate at all. Could be what happened in the first place. They got too dry once, you watered and thought they were OK, but basically, they got no water at all.
