[ICOM] Help with SM-20

[Doug Shields]

Hello everyone,
     I just received an "excellent condition" SM-20 microphone.
Unfortunately, there is no output from the mic.  Pushing the PTT button puts
my radio into transmit mode but there is no audio.  Is there a good method
for testing the mic element?  Any hints or suggestions on how to approach
this?  Does anyone know if I can get just a replacement element from Icom?
Any help would be appreciated.

Doug  W4DAS