[Icom] HM-56A microphone schematic

[William D Rourke]

Hi All,
     Does anyone know where I can obtain a schematic for  the HM-56A
microphone?  I have one which wants to key up when plugged in to the
IC-229H without provacation!(sp?)  ie: ptt button is not depressed.
I had just programmed two telephone numbers into the mic when this
problem started.  Acts like a problem with the onboard CPU or possibly a
ptt switching transistor.  Anyone had this problem?
Thanks,
Bill, W7ERH, Shoreline,WA