I have a very well maintained 97 M series. The volume **** on the radio does not work frequently. Turn it clockwise and it might raise or lower the volume. Same with CCW. Only moves the volume either way in slow increments, even if you give it a 360 turn. Sometimes there is no change at all with rotation. I did notice last year that it got better with use through the summer, but not so this year. Humidity does not seem to be a factor.

 

Hey, I found that if I apply an angular pressure from top of **** to bottom (pull on top of **** while pushing on bottom) while I adjust, the volume control will work fairly well. Thanks for the thread!!