[Yaesu] Yaesu FT100D VOX issue

[John Geiger]

I recently picked up a used Yaesu FT100D (I had forgot how much I like this
model) and the VOX doesn't seem to be working correctly.  When I turn the
VOX on, I have to set the VOX Gain at maximum (100) to get it to trip the
VOX, and even them it doesn't do it all of the time.

Has anyone else dealt with this issue and found the solution?  Is it
possibly a problem with the microphone?  The down button doesn't work on
the stock mic I got with the radio, but the audio gets good reports, so it
is working.

73 John AF5CC