Phalaenopsis Orchid leaves turned white and limp!

[Bch13]

Hi guys,

I'm not sure if this is a disease but it doesn't seem like sunburn either. I recently was gifted an orchid that isn't doing very well. You'll notice some shrivelled roots in the picture, but these were preexisting before I had the plant. Despite these shrivelled roots, I examined some of the other roots in the pot and they seemed fineZ.

I have had the plant for about a week now and it seemed to be doing alright. I have been growing it in bright, indirect sunlight alongside my other orchid (which is perfectly happy). Last night I noticed that all the flowers had died and had fallen off the orchid, but it's leaves looked fine and the typical green colour. Today I came home and the leaves had turned limp and white. Again, my other orchid has been grown in identical light, heat, and watering conditions for months and is fine.

Does anyone know what is causing this? Do I need to get rid of this new orchid?

Any help is appreciated!!!!