Fishfinder problems

[alancollins]

I have a Navman 440 fish finder which goes on the blink whenever I encounter rough water.
Even the wash of another boat is enough to give me a blank screen, without even a bleep to tell me the unit is shutting down. When I press the on/off switch it starts up again, only to shut down at the next bit of movement. I only use it for navigation purposes, so the fish finder features are redundant. I would just like to know when I'm about to run aground!
Any ideas?
alancollins

 

[Major Catastrophe]

You've got a bad earth or other connection.

Maybe time for a new transducer.

Mine went on the blink and gave false or garbled reading. £60 cured it.

Check your power feed first, clean the transducer connection to the back of the unit and get some to gently wiggle the wire close to the transducer to see if that causes it.

Do this in calm harbour or out of the water.

This may help.

 

[hlb]

I've got a Navman FF, Used mainly as a back up. Mostly the screen is blank. Unimpressed.

 

[alancollins]

Thanks for that. I'll re-check the connections and if that doesn't work think about a replacement.

 

[LittleShip]

I have a Navman 440 fish finder which goes on the blink whenever I encounter rough water.
Even the wash of another boat is enough to give me a blank screen, without even a bleep to tell me the unit is shutting down. When I press the on/off switch it starts up again, only to shut down at the next bit of movement. I only use it for navigation purposes, so the fish finder features are redundant. I would just like to know when I'm about to run aground!
Any ideas?
alancollins

When you find out what causes it let me know........ mine does exactly the same thing when ever there is any air in the water.

Tom

 

[Major Catastrophe]

When you find out what causes it let me know........ mine does exactly the same thing when ever there is any air in the water.

Tom

Hang on there.

Your problem is the garbled display due to air/water interference, the OP's problem is that the unit powers down, so I surmise it is an electrical dry joint or earth or a short somewhere.

 

[Kawasaki]

Now Tom , you must listen to Major Catastrophe, you know His reputation ref the subject of fishfinding.
Air in the water
Now here's a thing
Do flying fish hold their breath when 'flying'?
OK, I'll get me coat on
Probably work that one out better, after a few down the Liverpool Arms!

 

[LittleShip]

Hang on there.

Your problem is the garbled display due to air/water interference, the OP's problem is that the unit powers down, so I surmise it is an electrical dry joint or earth or a short somewhere.

Ok smartarse..... I concede but I still have my problem that somebody may have an answer to, other than pointing out my reading skills.

Tom

 

[Major Catastrophe]

Ok smartarse..... I concede but I still have my problem that somebody may have an answer to, other than pointing out my reading skills.

Tom

You wanna try not looking at the computer screen through the bottom of a glass.