[Elecraft] no side tone on K2

[MARY HAYS CARNEY]

Don:
After much backing and resoldering, I finally got my K2 on the air. (The problems were popped then mismatched finals.)  Unfortunately, the side tone has stopped working, either in setting the tone or level from the menu, transmitting or in the test mode.  I can get power out on key down, just no tone.

With key down, there is no ac voltage out of pin 4 of the DAC(U8) on the control board or at the drain of Q5.  There is 5 V dc on pin 1 of U8.  I assume that U8 is bad, but before I attack this chip, is there anywhere else to look? 

joe
KB3FBR