What's eating my Dendrobiums?

[Acharn]

I've got two dendrobiums that are being attacked by something I haven't been able to identify. It doesn't look quite like any of the pictures I've found, although it seemed to resemble cerospora a bit. Or maybe septoria? Can anybody tell? I'm thinking I just need to throw this pair out and buy some new ones. They haven't bloomed in a year, but they've had this condition for a few months now.