How do you troubleshoot a depth finder?

[hkeiner]

I recently bought a used boat and it has a depth finder that does not work. I would like to get the depth finder working if I can, but I don't know how to troubleshoot the problem.

I would first like to narrow the problem down to either the digital display gauge, the thru-hull transducer, or the wiring. After I narrow the failure down to one of these components, I can then determine if the problem is fixable and how to do so. When the motor is started, the digital display either stays blank or it shows a number which does not change regardless of how deep the water is. The display also randomly changes from being blank to showing the fixed number while the motor is running.

Is there a way to troubleshoot the gauge, transducer, or wiring with an ohmmeter or voltmeter to determine what is not working correctly? What other troubleshooting steps could I do?

Thanks

 

[Silvertip]

Re: How do you troubleshoot a depth finder?

It would help to know what brand and model the unit is. Is this just a depth finder or is it a fish locator as well? As for troubleshooting, the transducer is a sealed unit and not repairable so all you can do is follow the wire from it to the head unit and make sure the head end is connected and that the cable is not cut or damaged. The head unit is getting power or you would not see a number whether or not it changes. Try cleaning the transducer. If its a stern mounted unit, make sure it has not been flipped up. The head unit is also not field repairable. It would need to be returbished by the factory. Check E-bay for used transducers or head units, -- or here on iBoats if you need a new unit.

 

[hkeiner]

Re: How do you troubleshoot a depth finder?

Thanks for the quick reply. Here is some more information:

- The unit is a depth finder and not a fish finder.

- The in-dash depth gauge (head unit?) is about 1" by 2" in size and only shows numbers (i.e., the depth).

- The transducer is thru-hull mounted (i.e., epoxied to the inside of the hull pointing down) and thus not removable.

-At this time, I don't know the brand or model of the depth finder. If needed, I can try to see what is labeled on the gauge or the transducer the next time I visit the boat, which is currently in storage.


I understand that the gauge (head unit?) and the transducers are not repairable components but was hoping to determine which of these components has failed before deciding to replace either of them. Can I presume that using an ohmmmeter or voltmeter is not applicable to testing these components and that after checking for damaged wiring and poor connections, swapping out the components is the best way to go?

 

[eurolarva]

Re: How do you troubleshoot a depth finder?

You can buy a brand new cuda eagle for $75 here at iboats. These pretty much die and it is over. Most of the unit is one massive chip that was mass produced to be a depth finder and usually can not be repaired. Most newer electronics now a days is throw away and not designed to be fixed. Another issue is the unit is usually sealed so fog and moisture can not get inside. If you attempt to get inside it you run the risk of eveything getting damp.

 

[Silvertip]

Re: How do you troubleshoot a depth finder?

You could use an ohm meter to check the transducer for opens. But unless you know the specs what the normal transducer resistance is, you still can't tell if its bad or not. On my locators you can hold your hand on the transducer and feel it's pulse. Since the puck is epoxied to the hull you may not be able to feel anything at the sides or top. Eurolarva is right, any of the inexpensive fish finders have good depth indicators and you can actually see the bottom contour. Some even have shallow alarms which allows you to set it for say 4 feet which gives you just enough time to prepare for the crash when the alarm goes off. 8)

 

[hkeiner]

Re: How do you troubleshoot a depth finder?

Thanks for the practical advice that spending time and effort trying to determine which component is defective (i.e., in-dash digital gauge or transducer) is not worth it since these components can't be fixed and that finding a compatible replacement component would be difficult, especially since I don't know the brand or model I have to determine compatibility.

My initial hope was to do an easy fix by determining that the transducer was still good and replacing only the in-dash digital guage. This way I would not have to install another thru-hull transducer and do the associated wiring. I don't mind spending the extra money on a full kit. I was just trying to make my life easier.

Thanks again.

 

[gregmsr]

Re: How do you troubleshoot a depth finder?

Funny story......now. Thought I was in 150' of water but ran aground one late evening. Found out depth finder was in simulation mode.:^ Daughter had been playing with settings.

 

[ellis@cedarwoodco.com]

Re: How do you troubleshoot a depth finder?

Funny story......now. Thought I was in 150' of water but ran aground one late evening. Found out depth finder was in simulation mode.:^ Daughter had been playing with settings.

What exactly is that "simulation mode" gregmsr?

 

[gregmsr]

Re: How do you troubleshoot a depth finder?

Can't recall exact model of finder off top my head but for some reason there was a simulation mode in settings. It would give you a fake simulation on the screen of bottom terrain and fish. Don't know why. I think its a Pahrana (spelling), like the small flesh eating fish.......