Transducer problem

[Russdmorin]

I've had a 1650 DF with a 50-200K transducer for 15 years. The unit recently fried out (rust) and I found a replacement on ebay as I did no want to replace the transducer and antenna. The newly installed unit works perfectly in GPS and Plotter modes but the depth finder is a problem. The reading I'm getting looks like it's in a default mode - always reading about 5' depth.
The leak that caused the rust came through the viewer (enclosure tore in a storm). The rest of the unit is protected and always dry. All the connections in the rear are clean.
The transducer has never been a problem. How can I determine if the problem is in the refurbished unit or the transducer?

 

[Johnny Electron]

The transducer can be tested by the TDT1000 transducer tester by a dealer or the sounder could be sent in for evaluation. There is not an easy way to test a transducer without proper equipment other than by using process of elimination. You would take a known good sounder to connect to your transducer or a known good transducer to test with your sounder. Sometimes you can borrow something from a friend or marina.

 

[Russdmorin]

Thanks for the tip Johnny.
I called the boatyard where I winter over and he had an old transducer.( Forgot to mention that it's an in-hull transducer). When I removed the old one the reservoir was dry. I found a small break in the seal and repaired with 5200. Put mineral oil in and bingo- all's well . The reservoir was originally installed with west epoxy more than 18 years ago so I couldn't remove it without destroying it.

 

[Magnetron]

If it's been dry as a bone, with no glycol and you've been running echoes through it (dry) for any length of time, that's like shooting a transducer in the air. It is even that much more important that you get that transducer

tested by the TDT1000 transducer tester by a dealer

because it could have heated up in that time and rattled the elements inside itself loose. If you start seeing degraded performance from the sounder returns, we have to assume the transducer's health has been compromised before looking at the sounder next.

Hope this brings clarity, :sail

- Maggy