Yellow Leaves on Odontocidium

[Arkatrine]

Last Sunday I went on a trip out of town, and when I left my orchids were just fine. I returned Friday to find my Odontocidium with yellowed leaves.

I'm not sure what's wrong with them, if they're just old or diseased. Even the new growth is starting to turn yellow. I recently repotted this one, and took care of some nasty looking roots, but it doesn't seem like this would have any effect on him since it was about a month ago.

I'd really like some advice before I try to take care of it myself. You can click the images to make them larger. Thanks in advance!