A lot of people will say to toss it but as long as there is some green left I always try to save a plant. Yes, it may be a long shot and take a few years to recover but if it works you will have a nice plant. If it doesn't , you didn't invest much and you might gain some experience.

Phals are quirky, some will just die no matter what you do, some fight back in the worst conditions.

It is possible for the velamen on the outside of the root to be damaged but the root inside is okay. If the root is green and solid leave it, just cut away the brown mushy ones. I think the mold will go away after you repot it and let it dry out a bit.

After that I would try to give it as much consistency as possible. Keep it warm, medium light, and water regularly until it gets used to it's new environment. It may do nothing for a while , it may start growing right away, or it may decide that it is offended and die to spite you.

Just don't mess with it after you set it up. Some people keep unpotting it to check the roots or move it around to try different spots or different potting mixes and one thing they really do not like is change.

Good luck

Thanks for responding James. I'll tell you what I decided to do with it yesterday. All the roots except 1 had to be removed at the base because they were all rotted and soft at the base where they joined to the plant. That left me with the one root and that had to be trimmed back some because the end of it was rotted. So I have one short root left, that's it. I potted it in a mix of bark, perlite, and charcoal that I had been well rinsed, therefore it was premoistened. I will take your advice and keep it warm with medium light. The rest is up to it. It will either recover or not, I guess. I am rooting (no pun intended) for it to recover. :-) Again, thanks for responding and offering some helpful advice.