Humminbird 898C HD SI

[Roger W]

Looking for advice troubleshooting Humminbird 898c HD SI fish finder. GPS is working fine with lakemaster card. Issue is with sonar. On down imaging, can read the bottom occasionally at slow (less than 4mph) but digital readout of depth will start to blink. When that happens the DI graph stops moving and will restart moving when depth is found. At times the depth reading will stop blinking and have a crazy value (say 250 feet) but the graph is showing correct depth. Issue repeats on side imaging and 2D sonar. I have done a rest to factory defaults as well as hooked the unit up to a separate battery to isolate. Diagnostics on the unit report everything is fine. Have also seen the issue with the motor off so don't believe interference from engine. Thought the issue would be not having unit mounted low enough in water but with the issue happening at very low speeds that seems questionable.

 

Unit is mounted on back of bass boat. Thoughts on additional troubleshooting steps. Considering a Lowrance Elite-9 Ti2 as replacement. Thoughts?

[redmexican5081]

Does it give proper readings when you are not underway?  Is there anything directly ahead of the transducer on the hull? A live well inlet or discharge, a hull strake, any other thru hull fitting?  If you are only having the issue while moving, I’d say there is turbulence interfering with the signal.

[Roger W]

Some times it will give ok reading when sitting still but then digital readout will blink - usually comes back to correct reading.  I don't believe anything is directly ahead of the transducer.  I thought about interference but I have the problem with boat only idling - wouldn't have suspected turbulence at that point.  I will get a picture when I have a chance.

[Born 2 fish]

One thing to try is to set your depth. Take the unit off auto and set it to the maximum that you will be in. You can also try to reset to factory default. And try saltwater mode. See if any of that helps.

[Roger W]

I have tried taking it off auto and also the factory reset.  Even lowered transduer more last night with no change.  i have not tried saltwater mode.  It appears to be running the latest software version bu tI wonder if there is a way to reload the software - that might do more than just a factory reset.  Debating whether to buy another transducer or just replace the whole thing.  

 

Mounting pic attached.

[slonezp]

Did you call Humminbird tech support?

[Roger W]

Yep.  Not much or any help.

 

[redmexican5081]

From your picture it looks like the transducer may be angled too high in the rear.  I could be wrong but on my boat if the transducer isn't level with the waterline, like after I bump it off of something, it can have issues with getting a proper reading while at anything over idle.

[Roger W]

Understand.  I believe your perception may be created by the angle of the picture and position of the boat.  I went through a leveling exercise of taking the boat on water and using a level placed on gunnel to determine level while in water and then repeated on land to adjust angle of transducer.  So I believe that it should be level but heck worth a try at this point because I am very close to replacing the thing.

 

[Alex from GA]

I've always found the Humminbird techs are very good.  I'd try again and get another tech.

[Tennessee Boy]

Has it ever worked properly with the transducer mounted at the location?

[Choporoz]

Following. 

 

I have the same problem with my Garmin Echomap Plus in my kayak.   But I also had problems with Lowrance Hook 4 and 5 ...same thing...different kayaks, different transducers.  Nearly always in less than 6 feet, but once in a while in over 12 FOW.  I've only ever used auto depth, but maybe I should try to set to 'shallow' when in skiny flats.  Usually lasts for a couple minutes,  but sometimes as long as about 10 minutes. Rather maddening when transiting tidal flats that can leave some boats stranded for hours....not as much risk in kayak, but still a PITA.