Inherited Orchid with Issue
 

Yesterday one of my mom's friends dropped off these two orchids she inherited but doesn't want to take care of because she doesn't know how to take care of orchids. So now I have them. One seems fine and the other one has two leaves that have the discoloration seen in the photo. The center of the leaves is also soft - almost mushy. I don't see any pests or anything. Should I just let the leaves die off? I can't imagine they'll recover from whatever the issue is.

That's a leaf dying naturally. The plant was probably watered irregularly. I don't recall whether we've sent you to the beginning Phal grower's sticky thread before... from the left yellow menu select Forums then Beginners. Near the top look for the thread The Phal abuse stops here.

Interesting. I've never seen this happen on other leaves that have died naturally but the irregular watering makes sense. I have no idea of the plant's history.

If you want to be sure you need to repot it and give it some fresh media while you are at it. I'd remove the leaf as soon as it can be detached from the plant, it should be ok to leave it but if it is mushy I wouldn't want to leave it longer than necessary

always soak the roots thoroughly first to soften them, massage all around the pot to detach the roots from the outside then gently lift out the plant, remove old bark and fill in with new, just inspect the roots and put it all back after cutting away dead roots. The aim is to not break any roots