Type 300 Course Computer 12V

My ST7000 failed, black screen, Dead! It was connected to a Type 300 Course Computer. Due to the ST7000 being obsolete I purchased a new ST8001 I was told it was compatable. When I power up It displays "No Pilot." It is getting data as it displayed a shallow alarm.

First question is the ST8001 compatable with the Type 300 Course Computer?

I connected a short cable "2 foot" cable from the Yellow, red and ground Seatalk connector on the Course Computer to the ST8001 control unit with the same results. I also connected the same lead to the second set of Seatalk connectors on Course Computer...same results (No Pilot). Is there anyway I can test the Course Computer or is there somewhere I can send it for test and repair?

Thanks

Gary