Your Phalaenopsis appears to be planted in sphagnum moss so watering once a week is way too much. I think I see one live root down in the bottom of the pot and it is alive because it appears to be surrounded by styrofoam popcorn. It is in desperate need of a transplant. I suggest a mixture of 2/3 bark, 1/3 perlite or something commercial formulated for Phalaenopsis. If you do have one live root down there, chances are you can save the plant. To re-pot, hold the plant in the empty pot and fill around it. Pack the bark down as you go with your fingers. If you can pick the plant up by its leaves and the pot stays attached, you are done. If you can't, pack it down more. Then soak the pot and bark in a bowl of water for about 20 minutes to get the bark good and wet. After that, the once a week watering will probably be okay. But if you put your finger up into the bottom of the pot and feel moisture, don't water. Phalaenopsis do better dry than wet.
You also have bugs. BUGS!!
They look like mealybugs - incredibly hard to get rid of because they hide in every nook and cranny, including pots, potting medium and table tops. Get rid of every piece of the current potting medium and spray the entire plant, roots and all, with an insecticide like insecticidal soap or Beyers 3 in 1, or rubbing alcohol. Wash and sterilize (with bleach) your pots and, if the plant is sitting on a porous surface, like a wood table, spray it with the insecticide also. Peel the old dead leaf stubs back and spray.
After you treat for the bugs and re-pot, watch your plant carefully. The bugs will be back. You can kill stragglers with a q-tip dipped in alcohol.
Good luck and keep us posted.
Daisy
