Topic: 798 sonar problems

[Kentuckytiger]

I have a 2010 798 that was on the 2010 z518. When I purchased the boat the sonar wasn't working correctly but the side imaging worked fine. They dealership replaced the transducer but it did not work when I put it into the water but after about 30 minutes it worked correctly. For the next two trips it worked fine but after that nothing. I called the service dept. at humminbird an they suggested a number of changes to no avail. I shipped the unit back to Humminbird for them to look at it, but it came back stating there could fine no problems with the unit. I again put the boat in the water but the sonar read only 2.5 feet. After about 30 minutes it started working correctly. The side imaging works fine but the sonar has been a pain. In addition, when it did work the signal was weak.c
What gives.

[Humminbird_Greg]

Welcome to the Humminbird Side Imaging Forums Kentuckytiger.

Do you have only the one transom mounted transducer connected to the 798 unit?
Does the unit read the bottom reading correctly only when the boat is drifting or idling but not at higher boat speeds?
Is there someone else that you know that uses a Humminbird sonar unit that would allow you to test your 798 on their boat/transducer?  I see you listed a 788 so if you still have this unit try swapping then around and see if both units show the 2D sonar correctly or not.  Be sure to test them one at a time so there is no sonar cross-talk involved.

[Kentuckytiger]

Greg,
The 788 on the front is built into the front console and the local Ranger dealership installed a Ram mount so I could take it out of the dash to see it better but this is a bayonet mount, so I'm not really sure how to connect them now that there is a new plate on the 798.
It worked correctly today when I put it in the water but not sure why and for how long. Today, I was moving at idle and at a little higher speed (GT 30 miles/hr). I switched the settings to advanced mode and moved to saltwater mode. Not sure why it goes from working to not working.
Randy

[Humminbird_Greg]

Randy,
Did you ever check to see if your 798 is connected to two transducers or just the one CSi transducer on the transom?  I ask because it is sounding like you have a failing inside-the-hull 2D transducer.  The next time it starts to not work try pouring some water into your boat’s bilge area and see if it starts working again or not.

You should be able to take the 788’s mount apart and hand plug in the power and transducer.

This is going to be hard to troubleshoot until something fails permanently…