Corus echosounder and log both constantly read 'please wait', and make a beeping sound

[NealB]

I've no idea how old these two units are, but they were both there when we bought Celtic Spirit in 2017.

Both worked absolutely fine, and she was hauled ashore two and a half years ago with them both still working fine.

Celtic Spirit was laid up ashore from then, until midday today, when she was lifted in.

All went well, except the echosounder and log are both, at least temporarily, kaput.

As in the heading, both screens fire up, but read 'please wait' and beep.

I wait, and I wait a bit more, but nothing changes.

Presumably, it's a signal problem (or problems) between the transducers and the displays?

Any hints on where best to start troubleshooting will be most gratefully received.

eg Is it best to start at the transducers, or at the displays (the transducers are nice and easy to get at)?

What am I looking for: poor connections, persumably?

 

[NealB]

The tops of both transducers, and their attached cables, look clean, dry, and in good condition.

I remade all the electrical connections behind the display units, some of which looked very dirty. I gave the ends of the wires a good clean, and added some connector protector gel for bonus points.

Sadly: all to no avail.

Has anyone further suggestions, or , maybe even some inside information, please?