Mousenature!
Actually, your Phal doesn't look to "un"happy.
But do as Jim has said and remove that leaf.
I have 1/2 dozen or so Phals, and my potting mix consists of the regular orchid bark that you find at Lowe's/Home Depot, etc. , plus a little bit, maybe 10-20 % of the sphagnum, mixed in. Being epiphytes, the airflow is of utmost importance.
Sounds like you're very much aware of the basics as far as the light...No direct sun, especially in the heat of the day. I also mist mine, in between thorough waterings. But make sure that you do any misting's, or waterings in the AM. They don't like to go to bed damp.
Don't allow water to "pool" in the top of the plant. An invitation for crown rot, to be sure. Most of my Phals naturally grow at a 'slant', which enables quick drainage of water from the crown, though some insist on growing 'straight' up. These I double check to make sure that the crown is dry.
I think you're well on you're way to "reviving", and growing a beautiful plant! You'll start to see new, plump roots in no time!
Good Luck with it, and let us know how it continues to develop!
And again,
to the Orchid forum!
