Jim Willney here, new guy. Married, two great daughters
living 35 miles north west of downtown Chicago. I have the above orchid. New to me. When I got it home I mounted it.
This last week I noticed the leaves turning a redish purple
so I backed off the light. The leave are loose and pull off easy. The roots look good.
Welcome to OrchidBoard It is hard to tell what is going on without a good picture but I can take a guess. Crown rot will make the leaves easily fall off a phal. Crown rot is caused by water left in the center area of the phal where the leaves sprout out. This can be avoided by not watering directly over the plant into the crown and drying the area out if water gets in there.
Yes welcome When an orchid is mounted, I have read that the plant has to be at a 45 degree angle for the best chance to avoid water pooling in the crown. I am sorry that happened, maybe you can try to wait and see if a keiki forms at the base.
Look up "crown rot" there are some Youtube videos and many articles on how to treat. Sometimes the plant can be saved if caught early enough, if that is what is going on with your plant.