[Elecraft] K Line: Signal loss in a QSO

[rikoski]

I have a K3, P3, KAT500 and KPA500. I was listening in the middle of a QSO and lost signal.

I tested my antenna with a back up transceiver and the antenna and coax are good. 

The P3 still shows signals but only hiss comes out of the K3’s speaker.

Keying the k3 by pressing the attached foot pedal turns on the red Tx light on the K3 but the display on the KPA500 shows an asterisk to the left of the power out reading of zero on its display. 

No signal goes to the antenna and nothing besides hiss comes out of the speaker.

What should I do next? 

Thanks. W9ZD