Topic: 798c Si sonar looks like a dead sea not picking anything up

[sanchee79]

Need some expertise advice on this one. I have called Humminbird spoke to like 5 different agents and no one has a solution. I just installed a brand new transducer power cables etc and everything is working great except for the Sonar. I have a 797 on the front and a 798 in dash. The front unit shows baitfish ,fish, structure awesome the 798 is not showing anything remotely close. All the settings are set very similar but yet the 2 units are so far of. Can someone please help. The only thing I noticed was the noise filter setting is different. Please Help I dont want to have to send the unit in again I just got it back for another issue with the unit saying transducer not connected. Thanks

[Humminbird_Greg]

I would start with the same settings for both units and also with the most current software in each unit.  If that does no even things up than I would try swapping the units around and test them on each other’s transducers.  I do know that the circuitry for the 797 and 798 are different but do not know if this would account for the difference in what you are seeing.

[sanchee79]

I have done that and when I swapped the 797 in the 798 place it picked up the bait fine. Latest software is on there i just got the 798 2 months ago. Is there anything else that can cause the 798 in just the sonar to not read correctly. The Si and Di works great.

[sonar2000]

If you swapped positions and the working unit stays fine then it looks like the 798 is not right. 
Time for another HB call...
Chuckj