[Elecraft] Intermittent no rx signal

[W2LE]

Has anyone else seen this happen?

K3 sn 1114  5.14, with sub rx, not using QSK

Just put in the two KSYN3UPG boards and sometimes (maybe happening once 
in 30 CW contest QSOs) there is no receive signal after going from xmit 
to receive - no recv audio and no S meter activity.  But the P3 is 
showing the signals, in this case S7 to S9.

Tapping the sub button brings the main receiver back to life.

Help

Paul Franson  W2LE