NAV NET 3D- LF sounder

I can not get my low frequency sounder working. The HF is fine. I have had the electrician check the transducer and no problem there. I noticed a few other threads that spoke about this but I didn't find any resolution to the problem. Thank you in advance.

What sounder module is attached? DFF1, DFF3, BDS1, or DFF1-UHD.

I'll have to check and get back to you

How did an electrician check the transducer? You can't check them with a normal multi-meter.

with the help of furuno tech support they evidently switched the HF and LF and determined that the transducer is faulty. does that sound right? before we pull the boat and change the transducer.

p.s. we have the DFF3 sounder module

Yes, the sounder has two channels and either can run freq from 28 to 210, so using the sounder would have been a good test. Sounds like the transducer is bad. Why it went bad could be anything from improper tap settings, improper mounting, impact with an object, or just plain failure. If the transducer is under warrantee I would get with your selling dealer. Dealers source their products from different channels. For example if it is Furuno transducer the warrantee item would come to us. If it is an Airmar/Gemeco product it would go to Gemeco.