Is my Phal a goner? Roots are healthy but center part looks sickly.

Probably so, Lisa. Trim that yellow leaf completely back to green tissue, sprinkle with cinnamon, and try not to get any water on the leaves. The best way to keep water controlled is by bottom-watering. This was most likely crown-rot, likely caused by the plant being planted too upright, and water stayed in the crown (where the new leaves formed). If there is no sentimental value, you might just want to toss it and get a new plant. If you have a "nursing-instinct", baby the plant for a few months and see what happens. By the way, Phal. are very prone to crown-rot. You might get some Cattleyla alliance orchids instead. They don't have this problem. Also for me, scale seems to be attracted to some of my Phal. as well as snails. Neither nuisance seems to bother my Cattleya orchids.

Good luck.

Daisy, have you had any luck bringing these crown-rot plants back from the dead?

No, it's a goner.

@5601Lisa, I mentioned that the Phal. was planted too upright. If you are going to grow Phal., be sure that those plants are tilted. That way, when water gets in the crown of the plant, it will drain away. Also have some air-movement so that your plants can dry out between waterings. That's true for any orchid you grow.

Here are some examples pictures below. Also, I generally now only grow compact-size Phal. and those will typically be mounted. You don't have to worry much about water issues with mounted Phal. As they do in nature, they will grow at an angle. They know what to do.

Ken, your plans are in terra cotta pots, right? Mine are in plastic pots with vertical slits for drainage. Think I should repot?

I would not re-pot right now, Lisa. The plant is going to have a tough time surviving and you don't want to stress it.

I generally grow all my "standard-size" Phal. in clay (unglazed, orchid pots) simply because Phal. gets top-heavy. I just go ahead and grow them in clay so I don't have to worry about them tipping over. But again, those plants you see are old ones (sold, long ago) and I really don't like to grow standard Phal. any longer. If my compact growers are not mounted, they are growing in mesh-pots, maximizing air-flow to their roots.