AKG D series mic fix-up

[Martin]

we've been lucky enough to be given two akg D series mics, a D30 and a (i think) D20

the d30 works wonderfully! very quiet and lots of polar patterns to choose from makes it a vast contrast from the mainly newer and predominately vocal condenser mics we have at the studio


i managed to get the d30 working but i think the d20 is busted, can't get any noise out of it what-so-ever...

question is, who do i go to to service/check-out this thing? and is it worth it or are parts a pain seeing as the thing is close to 40 years old