Nasa Target echo sounder and log: both stopped working

[NealB]

We had our first trip out on Saturday, after relaunching, and neither the depth sounder, nor the log are working.

Both displays come on, so they've got power.

I can hear the log's paddle wheel spinning, but log reads "Speed 0.0 knots" (even when the GPS showed 8.5 knots).

There's lots of oil in the tube for the echo sounder's transducer. The echo sounder reads "Out".

No connections have been disturbed.

The hull is very clean.

Both units are old (certainly over ten years).

Should I just lash out a couple of hundred quid on new units, or is there much I can test first? I haven't got a spare transducer to try.

Thanks for any tips.

 

[MM5AHO]

You must have good ears to hear the paddlewheel turning, but if it is then..

It seems strange that both go out at same time. That suggests something in common with the two. Power supply? (but you said both displays light up)! Are they two separate instruments (not a combined display).
"out" suggests out of range, not hearing a return signal from the transducer. Can you try it in really shallow water (<5m)? If it still doesn't register a depth, then either transducer or head unit faulty. Transducers for this are about £30, so that's the low cost starting point of replacement. If that doesn't fix, then headunit too, and you have a whole new system.
For speed, do you have a plug to fill the hole if you remove the paddlewheel to see it? You can then spin by hand and have someone watch the display.

 

[neilf39]

If it's two different head units then either you are very unlucky or it is something in common. Power seems the first thing. Is the battery ok and are they both fed off the same wire to the battery. Wonder if you have corrosion or a low battery and either the voltage is too low or insufficient current can pass. It is enough to allow the displays to work but not for the sensors to work.

Have you checked the wiring where it enters the head unit and at any locations where you have a connector/joiner/switch in the circuit. Even if voltage checks out at the instruments corrosion could limit current draw. Are you 100% certain connections have not been disturbed.

 

[VicS]

We had our first trip out on Saturday, after relaunching, and neither the depth sounder, nor the log are working.

Both displays come on, so they've got power.

No connections have been disturbed.

.

As Geoff says its odd that both should fail at the same time. Despite the fact that both displays appear to be working I think I would check the power supply anyway as it is the only thing common to both.

Perhaps the connections for the transducers should be "disturbed," cleaned and reconnected after a light spray with a contact cleaner.

 

[PotatoNavigator]

In my experience the connectors are susceptible to rusting.

 

[NealB]

You must have good ears to hear the paddlewheel turning, but if it is then..

It seems strange that both go out at same time. That suggests something in common with the two. Power supply? (but you said both displays light up)! Are they two separate instruments (not a combined display).
"out" suggests out of range, not hearing a return signal from the transducer. Can you try it in really shallow water (<5m)? If it still doesn't register a depth, then either transducer or head unit faulty. Transducers for this are about £30, so that's the low cost starting point of replacement. If that doesn't fix, then headunit too, and you have a whole new system.
For speed, do you have a plug to fill the hole if you remove the paddlewheel to see it? You can then spin by hand and have someone watch the display.

Thanks Geoff.

It's very easy, in fact, to hear the impellor spinning (even with my poor old ears). If I twist it through 90 degrees, it's clear which way is in line with the wateflow, and which is across.

I certainly agree that it's seems too much of a coincidence for the two separate units to expire at the same time.

Coming across the Rays'n on Saturday, I'd guess the water was well below 5m.

 

[NealB]

neilf39, Vics and PotatoNavigator.

Thanks for those thoughts on connections. I'll have fiddle with them next time I'm out (maybe tomorrow or Wednesday).

 

[GrahamM376]

Thanks Geoff.

It's very easy, in fact, to hear the impellor spinning (even with my poor old ears). If I twist it through 90 degrees, it's clear which way is in line with the wateflow, and which is across.

I certainly agree that it's seems too much of a coincidence for the two separate units to expire at the same time.

Coming across the Rays'n on Saturday, I'd guess the water was well below 5m.

As others have said, it's unusual for both to pack up.

Can the log be removed in the water? If so, check the magnet hasn't been spun out when power washing.

The sounder doesn't need an oil bath, it can be attached to the hull with a blob of silicone or similar so may be worth checking that way.

 

[ghostlymoron]

I should disturb the connections give them a squirt with the much maligned WD40 and reconnect. Including the power supply.

 

[ghostlymoron]

Can the log be removed in the water? If so, check the magnet hasn't been spun out when power washing.[/QUOTE
That wouldn't account for the depth sounder.

 

[VicS]

I should disturb the connections give them a squirt with the much maligned WD40 and reconnect. Including the power supply.

Provided you mean WD40 Electrical contact cleaner spray

 

[GrahamM376]

Can the log be removed in the water? If so, check the magnet hasn't been spun out when power washing.[/QUOTE
That wouldn't account for the depth sounder.

Obviously. As he says there is power to both displays and each has its own transducer cable, there may be two separate faults. It's not uncommon for magnets to fly out of log paddles when someone blasts them directly with a power washer.