Vicky wrote

I've got plenty of phaleanopsiii, and I am fine with them. I have
killed every cambria I've had quite quickly. I've had some cymbidium
that have lasted a few years but all gone now. And I have one more,
which I think, from some googling, is a dendrobium. It is still alive,
and it used to be really really good. But now it's really unhappy.
It has flowers! But 75% or more of the plant is dead, or at least
dead looking. The one stem/stalk which has a flower stem on it is
fine*, but the dead stuff is ... crunchy looking.

The live bit has a case of scale insect. :-( But I can /probably/
get rid of that with a bit of care, and if I don't mind discarding
the flower stem (which would be a shame)

It's in a very warm and sunny south facing window, and it seems to
like it there. I think it got into such a bad state after being left
unwatered for a few months, which was a bit unfortunate.

Any advice on how to help it come back? Or is it a hopeless case
and I should just keep it going as long as possible then bin it?

There are so many Dendrobiums and they come from all sorts of temperature
zones and climates.
From what you say it sounds like a tropical one, has a short flower spike
which grows up at the end of the cane?

http://www.tohgarden.com/orchid-care/dendrobium/

although I would change the watering to weekly or two weekly unless it's in
a tropical temperature heated room.

--
Regards. Bob Hobden.
Posted to this Newsgroup from the W of London, UK