Yep, unfortunately you have a case of root rot on you hands. The plants shriveled like they aren't getting water, and you are probably are watering them more because of the way they look. They're not getting water because they don't have roots to absorb water. This was probably started because the potting mix got old and began to decay. When this happens it won't dry out, and gets mushy causing the roots to stay wet all the time, and they rot.

I would not water any of these plants any more until you can pull all of them out of their pots and check the roots. If any of them have fairly good roots, then you can repot them, but any that look like the two in the last two photos I would not repot. (the plant that has the dead leaf in the middle looks like it might have enough roots for you to try to repot it now)

You are going to have to get better roots before they will survive being repotted.

I would suggest.....Get some plastic bags...if the plants will fit, bread bags are good. Take a pencil or small knife and punch several holes up near the top of the bag....Put a handful of moist orchid bark, or Sphagnum moss in the bottom of the bag, and put the plant in the bag with the bottom end with the root stumps down next to the moist bark. Tie the top of the bag, and hang it in a bright, but not sunny place.

If new roots begin to grow, let them get at least 4 inches long before you pot the plant.

Go on line to the American Orchid Society's web site and get their culture sheet for Phalaenopsis orchids. This will tell you how to properly care for the plants once you have them repotted.

If you have orchid bark mix ordered to repot these plants in, that's good. When you have a plant with a good root system under it, and want to repot it, here is what you do.

Get a pot that the plant will fit into without too much extra room....Pour out enough bark mix to fill the pot, and then put it in a pan or bucket and thoroughly wet it. Put a handful of the wet bark into the bottom of the pot and sit the plant on that. Fill in around the roots with the remainder of the wet bark until the pot is full.

Set the plant in a bright but shady location, and do not water it for at least a week or more. The bark will dry out and allow the roots that were bruised or broken in potting process to callous, heal and begin to grow again. Making the plant thirsty will also encourage faster root growth.

When you begin to water the plant, take it to the sink and thoroughly wet everything in the pot. Put the plant back in its growing location and wait until the pot is almost completely dry before watering it again. After about a month you can begin to feed the plant.....fertilizer at half the recommended strength, twice a month. The time between waterings will vary depending on the light, temperature, humidity, and air circulation around the plant. Don't water until it is almost completely dry.

Keep us posted on the progress of your plants.

Bill