Oncidium NOID with yellow leaf and black spots on leaf

[grasshopper]

I rescued this NOID oncidium from my office building and noticed that the older pbulbs were very shriveled, but that there was a new, smaller pbulb with one leaf growing. This leaf had a few very small black spots on it that almost like bumps on the leaf. They are not mushy...it's like they're freckles. Anyone have any advice on what these are and what action I should take?

I keep it in a windowsill (east facing) in my guest room, which has high/low temps of 78-62 degrees F and average humidity around 55%. I've got a humidifier running on medium all day, as well as the ceiling fan on medium 24/7. I transplanted to S/H about 2 weeks ago and I've noticed that the one leaf on the smaller pbulb is turning yellow. Still has the black spots, too. (Oh, and I water twice a week.)

I'm very new to orchids, so I'm hoping someone out there has some experience with what I've got. I've attached pictures of the whole plant, as well as close-ups of the yellowing leaf with the black spots. Oh, and i should point out that this leaf is the only one with spots.

Thanks!

[Brenda Aarts]

Good luck with the rescue Grasshopper. I have a few onc. types like this and I find that it is common for the leaves to be speckled with the black spots. I don't think it is a fungus/disease etc...so don't panic about that. (Wait for others to chime in and see what they think). The yellow leaf may just be older and time to go, or may be a result of plant adjusting to new conditions, I would cut it off. I don't grow s/h so can't say much on that, but 2 times a week seems a fair bit.