[Elecraft] No sidetone on K2

[gwwhatley at juno.com]

Hi all
My K2 suddenly lost it's sidetone.  No keying monitor (I use internal keyer), and no sound in tune mode.  No offset tone.   It has output to antenna or dummy load. 
 
All else seems to work ok.
 
Any help would be appreciated.  
 
Thanks, George, N4YM