I have a K3 and a KPA1500 connected via the Elecraft AUX cable. All was working well but I now have a situation that when I turn on the radio (and amp which powers on with the radio), the second line of the radio display wants to always revert back to the KPA500 or STANDBY display. 

 

As an example, I have a power on display on the K3 of HELLO TOM / WELCOME BACK. All during the scrolling of that display, I intermittently see KPA500 or STANDBY in the display. After that is done, I see KPA500 in the second line. If I try to adjust the CMP or MON level, the display continues to toggle between the CMP or MON and STANDBY.

 

If I disconnect the AUX cable from the amp, this does not happen.

Has anyone elver seen this issue?

Thanks.

Tom NY4I