The microphone is, in as new condition, and has been kept in the dust free zipper case that it came in...I used it a couple of times, more than five years ago and it has been in storage since then.
It's not a lead problem as I have used a different mic to prove the lead is working...I have also tried a little WD40 on the connector in case of corrosion...
I'm wondering if the diaphragm may be stuck due to inactivity? Is that a thing, I don't know.
Oddly I have a Beyer microphone (also as new and unused for many years) that seems to have the same problem.
Any suggestions would be very welcome...
Thank you