Oncidium Alliance trouble?

[ImABrat]

...I've had this Oncidium since 2007. Last spring, I separated the plant and it actually took to that well. Now, I'm seeing both plants are actually losing leaves and bulbs are dying. Looking at the pictures, the one on the left, when they lose their leaves, they have all looked this same way with the black spots. I don't see the black spots on the leaves until they start to die. What appears to be dying looks like the older bulbs maybe? The next couple pictures are pictures of their root systems left and right respectively. To me, the roots look really good. I didn't see what I think is root rot, no bugs or anything really to make me think something is killing these guys.

I'm just not sure what to think about them. These have never bloomed, which makes me sad but maybe next year if they survive.

Is there anything special I need to do for these or are they growing (and dying) naturally? They aren't as 'glossy green' as they were when I first got the plant, which concerns me about the lighting I have them in. I've had them in a couple different places, right now they are in front of a northeast window with a little morning sun/light. I also have a lamp lite on that table at night, as well.

Thanks for any help! I tend to let orchids take their course because I get rather nervous about how to care for them and whether or not I am doing the right thing, so any help would be appreciated.