A78 Ping enable issue

[Sallysea]

Hello again, a problem has developed with my older A78 in sonar mode. I get readings that appear correct in the dual sonar application but keep in mind I am out of the water. At least there is scrolling on the screen. The ping is enabled and the rate is 80.
When I switch icons to chart + sonar, it tells me there is no sonar and pings are off. A search for the transducer results in a blank screen. In the menu the ping is set to off and I cannot get it to switch on. I tried in other combination applications and got the same result.
I removed the transducer plug and all pins look good and reattached the plug.
Suggestions?